Good comment. Everybody can mine the public data of the fediverse, so you don't have to own an instance to do so. I think this is an interesting move from Meta. It is a different situation than the times Facebook and Google did embrace, extend and extinguish. Now the userbase of ActivityPub is much bigger than for example XMPP was back when FB&Google supported those. Let's see how this pans out.
CentOS is a good OS for servers. It also has a friendly web interface on port 9090.