that is happening regardless and is not a harm that is a result of federation
Yes, it is. Read this: https://ploum.net/2023-06-23-how-to-kill-decentralised-networks.html
There goal is to launch a twitter competitor with a lot of users and make money off advertising.
They can do that without integrating with the fediverse. The reason they’re going to integrate with the fediverse is to embrace, extend, and extinguish.
People have articulated all kinds of actual harms, including two possibilities in the OP, but frankly they’re irrelevant.
We know what Meta’s goals are, and we know they have absolutely no moral standards whatsoever. Exactly how they try to accomplish those goals doesn’t matter. We shouldn’t give them the opportunity to try anything.
We should be scared of Meta, and we should keep them as far away as possible. Anything else is reckless and stupid at best.
It’s not easier for them, and once there’s enough people to matter then it’s too late to kill it. The fediverse is growing, and they want to stop that before the fediverse is big enough to matter.