Basically Meta will try to join the fediverse build up a bunch of users and get content. Once they become the biggest instance they will build up a wall to kick all the competition out. It is what google did to XMPP. https://ploum.net/2023-06-23-how-to-kill-decentralised-networks.html By signing the anti fedi pact we are esentially preventing a corporation from taking over and ruining it for everyone else.