I think the issue being missed here is that Meta will ultimately aim to suck all users into themselves, and then once they feel they’ve done enough of that, they will go completely closed, even potentially forking the protocol itself. If any legal attempt to stop this is made they will bog it down with hordes of lawyers for decades.
Their goal is not to help fediverse, it is recognising fediverse to be a threat and aiming to absorb it. Literally no different to how reddit slowly absorbed all internet forums into itself, killing the distributed internet.
Fediverse is attempting to bring back that distributed internet and they’re trying to find ways to kill it. All corporations seek monopoly, it’s how capitalism works.