I think the be careful what you do on Facebook is implied. He's highlighting something that's less expected, where you may need to be careful what you do on Windows systems.

They mentioned Microsoft updating privacy agreements at the same time as other companies, and OP mentioned that the context was a discussion of a Windows ultra-keylogger type of feature, the implication is they're in on this shit too, and Linux is a way to not use Windows.

They literally work for the Fediverse branch of meta, sure its an evil corp and zucks intentions aren't exactly pure (more than likely an effort to lower server costs) but it is something likely to put more eyes onto the fediverse which I definitely think will benefit the fediverse in the long run.