This feels like a psyop full of traps and reverse traps. That this is pretty much a googol-IQ level play from MKZ-3000 or its strategist co-processors.

Consider:

Facebook/Meta already knows that the kind of people who have already migrated to the Fediverse (Mastodon, Lemmy, etc) are the type mistrustful of corporate interests in the internet—anti-FAANG and all that. Facebook meeting-up with people from Mastodon, devs and/or large instance admins (hence, Mastodon.social and Mastodon.world instance owners), would put those people in a frenzy.

Add an NDA to that, which can have the overall effect of an injunction, super-injunction, or even a hyper-injunction—even if that kind of thing isn't legal in whatever jurisdiction the NDA is in (please keep in mind IANAL), and you've got a recipe for people really getting suspicious.

What for? This would shake confidence in Mastodon (and the Fediverse at large) by making it seem that it's already compromised, further scattering people across different solutions.   Even more insidious is that this gives Facebook/Meta an easy way out just by pointing out that it's "too conspiratorial" to think that Mastodon is compromised (because of a meeting).

Is there a way out of this dilemma? I think there is. By giving a Fediverse platform, and their instance admins, just enough trust for them to do their jobs. This is a very hard balance to achieve tho, and personally, I veer too much in either direction: either not trusting people enough, or being too ready to give them the benefit of the doubt.