Someone posted that Honkai Star Rail had different visible panties for some of the girls in the beta but all gone for the full release.
Same thing happened in Genshin so i'm not surprised. Ayaka had striped panties in the beta but after release it's granny panty. Fischl only wears a leotard in promotion materials but got stockings to cover her legs up at release. In general you can see that a lot of females in Genshin got "covered up". They're wearing some sort of weird hot pants/bloomers that doesn't mesh well with the rest of the outfits. Those fabrics looks "painted on" after the character model was already finished. It's clear that artists don't want to design characters like that but are forced to change them later on.
It's actually gotten progressively worse with Mihoyo. Honkai = all the cleavages, Genshin = some cleavage (Jean, Lisa, etc...), Star Rail = basically none at all, they're all covered up one way or another. Only exception is Himeko and she's a returning character so they might be afraid of fans throwing a riot if she's changed too much.