[vidarh]

There is no "global ban" for servers. You won't be able to move to a server that has defederated the server you're moving to or been defederated by it.

But you can still move to a third party server. If you desperately want to move from A to B and A and B are defederated from each other, you can even do that by moving from A to C and C to A as long as both A and B are willing to talk to C.