I'll be very honest, I don't think most of this will happen, but... if I was asked to make a wishlist it would probably be:
1. A new protagonist. To be honest, I found Cal very... boring? He was well-acted, but he didn't really have any personality traits to mention and he didn't really have... a place in the story? He really didn't have any stakes. Cere and Trilla had a connection with each other and a reason to fight, whereas the rivalry between Cal and Trilla was because of circumstance. Yes, Cal made decisions and had things to do, but he was barely connected to the actual emotional weight of the plot imo. I know that Star Wars always has a protagonist problem, but eh. It would be nice to have a protagonist with a connection to the plot and someone you can become attached to. I think having Cal as the protagonist harmed the emotional weight of the game. Another issue I think is something I call "the Inquisition mistake" because Dragon Age Inquisition did something similar: they kept the character backstory a secret until the mid-game instead of allowing players to experience the characters journey chronologically. For Jedi Fallen Order, I think it would have made the game better if we experienced Cal as a child as some kind of tutorial and played through the Order 66 level as the first part of the game because it would have given a more emotional connection to his story. Character introductions matter, and character backstory can provide necessary context to who they become, and I think that was missing in JFO.
2. A character creator. Customization and gender options would be great, I think. It would be nice to choose from alien races also and select outfits. Even something as basic as Jedi Academy would be nice and make the experience more personal, though more options are always good imo.
3. Dark side and light side story options/endings. I think it would be nice and make the game more replayable. It would also allow for more force powers to unlock like choke and lightning and more freedom in gameplay. Maybe you could start the game as a Jedi captured by the Empire to become an Inquisitor and it would kinda confirm some dark side/light side struggles.
4. Less clunky gameplay. I always think JFO has very "clunky" gameplay. Sometimes you can jump at a climbable wall, only for it to not give you the option to climb on it and you fall to your death. Sometimes in combat, it feels like Cal doesn't do what I want him to, enemies hit despite dodging, etc. I think smoother gameplay for the next game is something that I would enjoy.
5. A "story" difficulty with better balance. I play games for the story, not a challenge, and in Jedi Fallen Order, I don't think I'm happy with the balance of the enemies on the story difficulty. The game seems to want me to learn the way enemies attack through experiencing them but when I meet an enemy for the first time, I have no idea what their attacks are like or what they are in/vulnerable to. So I find it a little frustrating when I try and figure that out and the enemy attacks me with an ultra-fast unblockable attack I can't dodge or stuns me and then deals high damage. The combat balance feels fine while I'm fighting basic units, but as you move higher the worse the combat feels imo. I don't need ultra slow parry windows, I need more ability to learn the way enemies act before they start killing me or more vulnerable enemies, and more time to react for some enemy attacks. I didn't find the combat especially difficult... at least for the most part, but it was a little frustrating.
6. Some convenience. I find JFO very inconvenient to play. There is no fast travel, which is fine during the actual campaign but when returning to planets to pick up spare collectibles, it's something I need to travel around the map when I don't have the story to give me a reason to explore, even if it was just to return to the Mantis. I need to be at a meditation point to purchase new abilities and I can't heal/refill stims without respawning enemies behind me. Yup... I find it inconvenient, time-consuming and a little frustrating. I'm not easily bored, or anything like that, but I don't really find it fun to repeat things I've already done and I would find it more fun to skip some parts so I can focus on the things I want to do. I also got frequently lost/confused during the prologue on Bracca, so I think some form of quest marker/marker placement or path highlighting would be nice. And a non-confusing, actually useable holomap.
7. At least one slightly urban environment.
8. No existing non-JFO characters. So... recently I've been thinking about Star Wars, and I'm a little... eh... idk how to describe my emotions. I think I don't like the fact that so much of the 'new' material is actually focused on or including existing characters instead of giving entirely new experiences. I think it's a bad thing. I've loved Star Wars for around 25 years, and there are many characters I love both in legends and the new canon. But I think including characters where they don't belong can completely ruin stories, and deny Star Wars the ability to make new memories and expand on itself in the pursuit of nostalgia.
Take Battlefront II as an example. I love Janina Gavankar, and I was so excited to hear she would be playing Iden Versio in the Battlefront II campaign. I read the Inferno Squad novel, and during the first missions of the campaign I started to love the character. Because to me, her character offered a unique perspective and I think she had the potential to add an interesting story to the Star Wars universe. But part way through the campaign, the perspective changed from Iden and her Imperial missions to randomly having a level playing as Luke on Pillio as he was slicing up bugs with his lightsaber. And while I was playing that, I thought, "Why? What is his involvement in the plot?" and the answer is... well, he isn't involved in any way. The mission overall expanded on Del's motivation for turning traitor in the next mission iirc, but then Iden's story of becoming a rebel suffered. Instead of focusing on the motivations of the protagonist, it decided to focus on what Luke happened to be doing and it made the change from Imperial to Rebel seem sudden and unearned. Yes, the Empire trying to destroy Vardos was important and I understand her reasoning, but changing from a die-hard Imperial to a traitor in one mission was still too fast. People don't really change quickly.
And then after Iden became a rebel, Han, Leia and Lando all had missions dedicated to them. Battlefront II's campaign was a relatively short singleplayer experience, it didn't really have the time to waste on things that weren't relevant to the plot. But it wasted that time. So instead of Iden's story being a very relatable, emotional experience that could have explored her change from Imperial, to realizing she was actually a bad guy and the Empire was terrible, to slowly learning to embrace the ideals of the Rebellion, she transformed from Imperial to Rebel within one mission. And I think she deserved better than a campaign that decided to randomly have missions that were barely linked into her story. Because her story suffered because of it. It wasn't cohesive, there was no narrative flow or character arc to really mention.
Even in Jedi Fallen Order, the scene at the end of the game with Darth Vader, to me, had consequences for the story and the characters of the game. Yes, it was a memorable scene, and yes, it was "awesome", but I really think it did more harm than good. The Second Sister only appeared a handful of times throughout the game, a relatively short amount for a primary antagonist, but I fell in love with her character really from her first scene. She was great. As the Second Sister, she was imposing, powerful, had music that put me on edge and was a genuinely difficult boss fight. As Trilla, she was damaged, broken but completely understandable and I had so much sympathy for what she had experienced and why she hated Cere so much. Her turn to the dark side made Anakin's excuse seem flimsy at best. Imo, the relationship between Cere and Trilla was the strongest source of emotion from the game. Whereas I found Cal boring, I was always looking forward to seeing the Second Sister and wanted to know how her story would end.
In her final scene, Trilla was finally confronting the source of her pain. It was the climax of her story with Cere, and I can't help but feel that it was completely wasted and disregarded for something that didn't actually matter to the story. Because of Vader's arrival, it seemed that Trilla, like Iden, changed too quickly. People don't really undergo complete changes to their worldview based on a single conversation, and I don't think she was ever allowed to process her pain and grief. Especially because she essentially had been betrayed by her master and subjected to torture as a direct result. She would be suffering from severe PTSD, as a minimum, and Cere admitting her guilt and apologizing, while it could have helped slightly, wouldn't be enough to change her heart imo. It would take time, and she would have probably never fully recovered - that is, assuming she decided to try to help herself instead of remaining an Inquisitor. It could have happened both ways, really. With Cere and the Empire, both caused her pain - but until Vader, at least the Empire hadn't betrayed her.
But Vader happened. And while I enjoyed the ending, I don't think I liked it. It makes Trilla seem like she released all of her hate for Cere only because she apologized (she used the past tense)... and then she died, and I found it unsatisfying. Pain doesn't just vanish like that. I kinda have the impression the idea was to wrap up that part of the story quickly so Vader could be in the game. The main conflict of the story was never really resolved in any way though, and I'm not sure the ending was a good trade. It didn't offer a boss fight because it was more running away, and it only really gave us information we already knew, that Vader is powerful and Cere struggles with the dark side. I would have preferred it if the ending had focused on Cal, Cere and Trilla instead of killing Trilla and (quite literally) throwing Cere away to introduce a character who hadn't even been part of the story until the last few minutes of the game. I think it it harms the stories of the actual characters and does them a disservice.
So yup, I think there are always consequences for not focusing on the characters in a story to focus on others. It doesn't only apply to video games though, The Rise of Skywalker did exactly the same thing and with exactly the same result - making the entirety of Rey's story about who her parents were and making her a literal conduit for other characters which was a complete waste of a character who had been needing more involvement from being very passive in The Force Awakens to having no character arc whatsoever in The Last Jedi. I think the only time it has worked for me is Rogue One, where Vader was so removed from the story and the scene with the rebels kinda alleviated some of the sadness from watching people die. So, I think Fallen Order 2 should only have new characters or characters introduced in Jedi Fallen Order, because I think the characters involved always deserve better than to be ignored, dismissed or have their stories shortened to focus on others who, while being great characters, are narratively unimportant. To me, Star Wars is bigger than Luke, Leia, Han, Lando, Chewie, Anakin, Darth Vader, Ahsoka, Obi-Wan etc. It's bigger than any one character, and it's bigger than all of the characters. But we have a Star Wars franchise that seems determined to inject existing characters everywhere. One thing I really don't like is on the back cover of the Aftermath: Life Debt novel, one of the praises it has featured is essentially, "The book explains what Han Solo was doing after Return of the Jedi!" and it baffles me every time I read it. That isn't a praise. A book can't and should never be praised for giving exposition about where a particular character was, but that's the reality of Star Wars atm. But, that's a little off-topic. Anyway, every time a character is introduced somewhere they don't need to be, it makes the Star Wars galaxy feel smaller imo, and it kinda risks becoming repetitive which makes me less likely to love things. Focusing on new characters makes the galaxy feel larger and more filled with life and adds more perspectives and stories to the canon and that's something I want more of. More planets, more people, less familiarity. When a story introduces characters, the story should be about those characters. No exceptions.
9. The return of Trilla. Yup. It is possible that she survived Vader's attack. Especially if it didn't sever her spine, she could have survived long enough to get medical attention or escape? People have survived worse in Star Wars :P I really would want to see her again, even as a prequel or something like that. Her character made Jedi Fallen Order a memorable game for me. Maybe she's chosen to fight the Empire for betraying her, maybe even killing other Inquisitors while still being on the dark side. We don't really know what happened to them.
10. No Star Wars tropes. So, no planet destroying weapons, no ultra-convenient weakness in the bad guys plan that allows its destruction, no "my apprentice is dead... from a certain point of view but they're actually totally the bad guy now and very much alive" (I didn't like that I could guess the outcome of JFO based on one conversation with Cere. I thought "I've seen the original trilogy so many times, I know exactly where this is going"... and then it did exactly that without deviation). No "I am your father/other family member". And really, a bad guy that isn't redeemable would be nice, though I guess I don't really have any preference if it's earned and doesn't come from a single conversation.
11. More freedom to use force powers. Jedi Fallen Order has some really nice combos and animations, but I can't help feeling that it kinda discourages me from using them by making force powers so limited. It would also be nice to have an auto-regenerating force bar because Jedi shouldn't gain force power through killing enemies... It was weird.
12. The option to use a single lightsaber, double-bladed lightsaber and dual lightsabers separately for more gameplay variety. Single lightsaber could be generally pretty good but not great at anything, dual lightsabers could be better at melee combat but limit some force powers and double-bladed could be better at offense with faster strikes but weaker on the defense, though without limiting force powers. Maybe something like that.
13. No spiders, zombies, sharks/underwater creatures. I'm arachnophobic and Kashyyyk was terrible. I also hate enemies like zombies chasing me because it's not nice, and I think I have some thalassophobia also because whenever I enter a body of water in a video game (and irl) I'm afraid of seeing a shark, whale or miscellaneous sea monster. My fiancée had to complete the AC Odyssey underwater segments for me because I couldn't... it was a relief for the waters in Fallen Order to be empty, though the Empire should have Death Starred Kashyyyk. Also Dathomir.
14. More linearity? I really think Bracca and Nur are the best levels in the game, whereas I think everything else is... kinda meh? I think the problem that the levels needed to be designed for players to return to them, but I think that limits things too much. In an environment you only visit once, it can be dynamic - like Bracca on the moving train. It can shift and change and provide players only one route forward. Buildings could be destroyed to block paths or they could take place in areas that can only be accessed for a limited time. There are more possibilities for single-use environments and it would help to streamline the game compared with JFO, where I never really found traversal very fun and returning to the planets after the story more of a chore. It would work well with the option to replay story missions, I think.
15. A better story. I kinda think JFO's story is a little... uninspired? Around the time I returned to Zeffo, things... well, I wasn't really happy tbh. I didn't really feel there was a story to guide me and most of the time... I'm not sure there was? Most of the game felt to be travelling to a planet, fighting through many enemies, reaching the goal and then being told I had to go to another planet to do exactly what I had just done to be told I needed to travel to another planet only to go back to the first planet. To me, that isn't really... a story? There were sub-plots on some planets but nothing to really have motivation. Things kinda felt a little aimless without the Inquisitors around and it's only after finding the holocron where things felt to... happen?
16. A manual save!
17. More people, fewer creatures in combat.
18. More things for characters to do than sitting on the ship. Not companions necessarily but they could be better used imo.