I think it depends on world pretty much
would i love to see magic town in ts4 style? heck yeah!
would i love to see sunset valley? :/ not really
I think some of more themey worlds from past games and spinoffs and such could definitely be cool to see again
but there is also many worlds in past games that make me just think: :/ meh
and I also think some themes are good but they could definitely do better in sims 4 if they tried cause i feel especially in ts3 too much was lost in the endless sea of box houses
and even after all that i might just like new concept more