Mark's statement was worded carefully in that he stated access would not longer require your _personal_ Facebook account. I interpreted this to mean you'll still need a Facebook account, but it would be through a Facebook for Work account (although I'm not sure if today these are distinct entities).
nah, they'll create a new single sign on service for Meta and you'll be required to have a Meta account (and Facebook and Instagram and WhatsApp will all also require a Meta account).
More just instead of a star with each on a spoke and FB in the middle, Meta will be in the middle and FB just another spoke.