good question, i don't know how the team can do that exactly but i bet some of the personalities can be in basegame
like Love Children, i think it can match with the basegame
each sims is different of course but i'm sure some of the adult loves to be around the kids
they like get a sad moodlet if they are not around the children
Fisherman since we can fish in the basegame world
like the name have guessed your sim loves to go fishing and if they don't do fishing for awhile your sim get a sad moodlet
(just to name 2 things)
i just came up with these traits that can be in basegame😊😊