His lack of worry seems to be founded in Meta Defederating, not federating, though. Meta would do more harm by being a part of the community than by leaving a ways down the road. It seems like a particularly myopic view of possible problems with Metas move.

Saved for later, but small startups/operations always know the will play second fiddle and be the smaller guy.

You absolutely should be. If Mastodon instances will start federating with Meta I will defederate them. And move my accounts from any instance that federates with them.