Let’s not get into hypotheticals. You know as well as I do that a large bit of Facebook’s early growth story was their brand and their reputation. That name may have been dragged through the mud in the past few years, but it still means something, and its not without value despite the recent rebranding on the parent company front.
Meta retains the exclusive right to do business using the Facebook mark and they’ll continue to enforce it. It’s the same story for any other company, and it’s a form of monopoly that the government grants, not something that would be enforceable otherwise.