So your making a asumption that incorect 5e adaptation of the rules is going to stay,
Yes, I don't expect major changes to happen for 1.0. I wish for a balance pass, but that's about it.
I am not gonna dig out interviews, but from what I saw Larian was very open on their willingness to change rules they don't like. They walked back on some of those changes, but I expect the majority of them will stay.
BG3 as is, IS based on D&D 5e. It is not a 100% faithful adaptation, but it is an adaption.
