"I also understand how that could be seen to go against the point of federated social media in the first place…"
Federating with Meta is different from federating with individuals. It's like letting corporations be treated the same as natural persons for the purposes of voting in political elections and exercising other civic participation rights.
Natural persons may have a variety of motivations for federating. Corporations have only one: to increase profit.
And please don't say "federate now, revisit later if needed." Recall the fable about the scorpion and the rabbit facing a raging flood. Said the scorpion, "oh please, rabbit, let me ride on your back as you swim across." Rabbit said "no, you'll sting me and I'll die." Scorpion said "no I won't; we're both in danger; I have children at home; we both want to live." Rabbit said "okay, if you promise not to sting me." So scorpion climbed onto rabbit's back, and halfway across the flood, scorpion gave rabbit a lethal sting. Rabbit asked why, and scorpion shrugged; "you knew what I was when you let me onto your back."