Neither of those two examples are at all relevant to this platform and their entire section about Meta and the Fedverse is complete speculation. This community isn't going anywhere even if they started acting hostile towards a decentralized platform as time went on. Having more communities on this platform is a net positive.
Can I ask you why do these examples not apply in your opinion? The XMPP one seems particularly fitting and actually maps perfectly to the Fediverse situation (so far), if I'm not missing anything.