Pre-nerf the 4o voice model had a wide range of expressivity, and it would match affect (still tries to do this) and idiolect of listeners if asked. Nowadays there's a list of accents that are considered "hate-ish" and a list that aren't.

I will elide the rant inside me that west coast 20 somethings get to decide if speaking in a certain accent is racist or "bad". But it's a heartfelt rant.