Yes they probably will.
But my point would be that with AP being W3C and not management by meta or a different company the ecosystem of it can survive.
And too be fair until recently I still used XMPP so it was never dead. I think it was just that almost no one ever heard about it before Google used it and also almost no one really cared about it while Google used it. So the resulting consequence was that once Google dropped off completely it went back to no one really using it (like it was before).
AP already having a decent user base (some million active users, official accounts and instances of big institutions like the EU commission e.g.) even without threads and a big eco system(very diverse platforms and projects), there is no need for any platform to adapt to anything coming from meta. Things are good (enough) how they are currently.
It's not that we need to compete or couldn't exist without Meta.
I think it's much more impressive that stuff that was added in 2018 and 2019 has a much higher probability of being deleted today than if it was added 2017...
Wonder if that has anything to do with covid and maybe new businesses models opened 2 years before failing and therefore websites of this companies disappeared.
Also I think it would be nice to see a graph of new websites being opened other the same time span.