I fail to see how that would generally impact people who interact from the fediverse side of it rather than Meta’s own instance. Like if Meta decides to no longer federate with the rest of the fediverse, that would be like all the normies signing up for Threads.net and not interacting with Mastodon at all right?
I think you are reaching.
People have a tendency to flock to centralized services. Even on here the majority of activity takes place on Lemmy.world, the fediverse already has a potential centralization problem.
With your point on YouTube, a fediverse version of YouTube that has a similar level and amount of content is impossible due to hosting costs. I have yet to see anyone willing to subsidize a fediverse version of YouTube.
I think that article is mostly fearmongering.
Most people using Mastodon right now are not following mainstream people on their feeds - they are mostly following like-minded people who have made the switch from Twitter. If their server decides to federate with Meta, it will actually improve their experience because they start following mainstream people from the comfort of their Mastodon feed. And if Meta decides to break ActivityPub (which I doubt), it will be back to the original status quo for most users.
And most mainstream people will not be signing up for Mastodon anyways, they will be signing up for Threads/Blue Sky.