Meta won't federate anyone. They don't want to host illegal content on their servers, that would be an absolute PR disaster for them. And this is what will happen if they federate with a random instance. Even clean instances will want to play tricks on Meta if federated.
They are the prototype of the mono instance federation. They want control. They want to attract the people leaving Twitter. I don't think they care about us, what they want to avoid is that our instances become too big and start to offer an alternative.
ForestOrca