I’ll be honest, I’ll assume bad faith from Meta until proven otherwise.
A good example here is the first version of Google chat, which federated with jabber - until it didn’t. I was quite vocal about converting my friends to it because it was an easy entrance to jabber, with a brand and interface they trusted.
Then once it was big enough, jabber federation was cut off and we looked like the weird outsiders.
Federating Meta will feel like a win right up until it doesn’t.