February 2020
I am on my fourth generation and the same sims walk up and down the streets. They must be immortal. They are downtown, in the parks, restaurants ...is there any way to get new neighbors?
February 2020
I'm not sure if they get replaced, maybe by adding them to the family and retiring them properly. But this might also just leave you with an empty sidewalk.
The ancient NPCs is something that was reported as a bug:
https://answers.ea.com/t5/Bug-Reports/Open-Ancient-elder-NPCs-don-t-disappear/td-p/6986428
March 2020
I solved it! I did makeovers on almost all of them. Cost me a few Sims cash so I wouldn’t use my tickets but it was worth it! New neighbors!