I think this would be better as a full spin off more like Sims Medieval rather than an expansion for Sims 4. The biggest challenge would be getting Disney to let EA use parts of the Star Wars universe that don't fit the parts of the timeline they're currently expanding. At best, they might be willing to do something set at the time of the Mandalorian. It wouldn't be worth it to sink their time into developing a small piece of a crossover game without any major marketing campaign tie-ins. If Disney had advertised their theme parks properly in 2019 when they opened the lands, we probably wouldn't have even ended up with tie-in merchandise like JtB as an afterthought a year after opening.
All the things that would make an amazing Star Wars pack with also really screw with the lore of the Sims universe; adding the force would feel really weird wedged into normal gameplay, even stacked up against the occults we have. For me personally (and I know I'm the minority in this), JtB works better for being sectioned off because I can easily see it not as a new planet, but as a theme park I can send my sims to to play in. Just like in real life, they too can travel somewhere on vacation where the performers have zero interest in forming lasting relationships with them, and all the snazzy droids and sabers you buy that the CMs will pretend are real on planet are just decorative junk when they go back home with you.
