I think it's probably a good idea.

Did you know the Neanderthals were arguably more cultured, social, and collaborative than our Human ancestors? Yes the Neanderthals aren't our direct ancestors; they were another competing hominid. Humans killed them - but they also outbred them, including by breeding with them.

Humans are social creatures; the largest federated instances grow far faster than the smaller ones. Not just in absolute number, but in percentages. And Capitalism doesn't want competition in a free market; it wants a monopoly as quickly as possible. Any time a platform represents a threat to Meta's user-share, it buys it (Instagram, WhatsApp), and if it can't, it copies it (TikTok > Reels).

If a known name of a private umbrella like Meta/Facebook, Alphabet/Google, or Microsoft enters the fediverse, the following is likely to happen:

1. The fediverse gains notoriety, desirability and attention as private platforms enshittify.
2. It grows until this represents a threat to private platforms losing users to the fediverse.
3. [Meta]'s private users enter the fediverse via [Meta]'s instances; they're sponsored, accessible, visible or incentivised; they appear to have the lowest barrier for entry; they may integrate with the platforms they're still using.
4. New users in the fediverse in general likely join [Meta]'s instances; they're large, and where their families and friends are; they promise to be stable and have legal oversight; less likely to blackout from server error or admin corruption.
5. [Meta] slowly collects the majority of users in the fediverse.
6. [Meta] reaches a point of having >80% of the fediverse users anyway, and ceases the funding and technical support for federation and gateways, defederating and becoming a high-walled garden.
7. Other fediverse members are pressured by their colleagues, family/friends etc to make a [Meta] account so they can maintain contact. They won't leave [Meta] because they'd lose contact with anybody staying.
8. Other fediverse instances are forgotten as their users are pressured back onto private platforms.
9. [Meta] has successfully gained an effective monopoly over the fediverse.
10. [Meta]'s fediverse enshittifies.

TLDR: I think the Fedipact (or something like it) is necessary for the fediverse to ever become what we hope it one day can be. To allow self-interested private entities to stack territory in it will eventually see it consumed.