The problem is that the blocking will have to be layers deep. If your instance has defederated from Meta, but is federated with an instance that does federate with Meta, then Meta still has access to all your data through that mutual server. So not only would people have to defederate from Meta, they’d have to defederate with anyone who does federate with Meta. If everyone isn’t on board with this, it’ll cause a huge fracture to form.

Make no mistake: Meta wants to sell your data. They know all it takes is one server to federate with them and they’ve unlocked the entire fediverse to be harvested. I would not be shocked to see large amounts of cash flowing in exchange for federation rights.