I have very mixed feelings about this. It is an incredible amount of trust in Apple (both security and actual execution, esp given their history in AI), but it would be such a massive upgrade to individual user security that it is hard to comprehend.
Anybody who thinks this has any good, lost the touch with reality.
Imagine being unable to login because the AI decided that your master password is too weak, changed it, and locked you out!? hahaha
First Meta, now Apple, it's gonna be a hellava year :D