Yes, it is worth saying. In fact I was scrolling for this. There should be a way to adopt refugee communities with all its posts from other instances so as to not lose all the information when the server goes down for good. It needs consensus, but only from admins of original community and the new host, this last to prevent server abuse. Also, if communities can get merged, the list of instances hosting the community would serve both as redundant backup and as distributed (instead of fragmented) service.