@Cinebar I've made some calculations to understand how many simdays/simweeks are the 25 years between Sunset Valley and Sims 1, and the 25 years between Sims 1 and Sims 2, and if you ignored everyone else besides the Pleasant Twins, Dustin Broke and Dirk Dreamer it would fit almost perfectly as being 25 years after Pleasantview. The only thing you'll have to consider is that they would be a week to 5 days away from becoming adults/graduating from college. Also, Sims 3 Barnacle Bay would fit this too IF the Caliente sisters took the youth potion (cuz its supposed to happen after Sims 2, and we even have Goopy Gilscarbos wife and daughter in that town).
Anyway, I kinda understand why the devs didn't consider excluding Bella and Mortimer from the game/adding them as deceased... They are iconic and all, but they don't actually need to be in the game for me. They could be added to the gallery, as the "prompt" sims from CAS and used on trailers/renders of all packs. Also, they could be living with Alexander Goth and Cecilia Goth as ghosts in their mansion. I would love Bella and Mortimer as ghosts helping Alex raise his kids haha.
I WISH so badly the world builder devs would overhaul the worlds at some point. Like, remove the Caliente/Lothario, Goths and Landgraabs as they are (add them to the gallery for those who still want to play with them). And replace them with Barnacle Bay Dina, Nina and Luisa Libros, Alexander married to a pregnant Cecilia living with his ghost parents and an older Malcolm Landgraab IV (or the Malcolm that married Mom and had Dudley and Mimi... but still linking Johnny Zest to them... Johnny could even be the Bustin Out protagonist and Mom be his Mom Zest or something haha). They could also fix other issues like the BFF household not having the supposed drama going on, adding Iggy Pancakes to the Pancakes household... Adding affairs, enemies, etc
IDK... It sounds like an useless thing to do, but it would be a game changer to me.
I can make a post later explaning my calculation to figure out the 25 years things and how other SIms 2 characters could show up in new Sims 4 worlds if you're interested. I didn't do it already cuz I've felt like Sims 4 players usually ignore me when I talk about premade sims cuz they don't care about them.