This post feels like fearmongering...
Why would Meta care about small instances? I feel like Meta would only see the big instances as pontential threat.
Honestly, this could actually be an opportunity for fediverse. I don't want Meta to harvest my data, so I would never make an account there. However I am interested in content/people from Meta and I can follow that from fediverse. I believe there is large group of people who think the same way and they may join fediverse if they haven't already done that.
Small correction, I don't want them to harvest data that is connected to me as a person. With Meta I have to give out many personal info that they don't actually need for their service to function. It's just a way for making more money.
Correct me if I'm wrong, but the only personal info on Fediverse I have to give is my email.