You assume that linking them will prevent any bans from propagating from one to the other.
Yes, because that's literally what they said was the reason for doing so in the stream, but I agree that until there's more clarity here and an explanation of how the terms of a Meta account would work then that's only of so much use.
Also if you have a Quest that is shared in the family, you don't need to worry about your family members poking around your FB stuffs anymore.
Can Facebook reliably find fake, empty profiles created just for Oculus?
I wouldn’t bet against them. They can tell if you longer on an ad, just by measuring how fast you’re scrolling the feed.
I recall reading something about having to have "an account in good standing", which certainly suggests that they can tell if an account is a real one or a dummy one.
My friend and I bought two Oculus Quest 2 for trying out out workrooms. We created new facebook accounts, oculus accounts as well as workrooms accounts. Both of us got the message that our accounts are not in good standing when trying workrooms. See screenshot from another poster in [1].