A "supposedly" whistleblower talked about this in detail. Meta was able to generate the whole life of a person from childhood to old age, and was able to simulate social media activities such as media posting, messaging etc.
Lex Fridman talked to Mark Zuckerberg about this just a few days ago [0]. It didn't sound like Meta is has good answers for how this should be done. So it seems unlikely that they'd be significantly more than 6 months into research like this (as the tweet chain says). It seems like Meta is exploring AI avatars, but for much more practical, menial tasks.
I documented the original text here: https://twitter.com/prakgupta_/status/1630669890138025984