OK Internet hive mind: working thru a half-formed idea. I like that BluesSky and Nostr and ActivityPub all learn off of each other's good ideas.  

And I do think that BlueSky's claims of more seamless migration of accounts is a plus, but one that #ActivityPub folks have line of site on how to improve. The other claim of innovation of BlueSky folks is that since they are not server dependent, but rather semi-centralized (if theoretically swappabley so) that if your local server dies or crashes the user is not stuck. 

Now those of us who have signed the Mastodon server covenant, promise to give three months notice before shutting down. But lets say an admin and his co-admins were all hit by a (large) bus. 
In short: If a Mastodon server goes belly up without warning in Mastodon or ActivityPub land and users have no account to migrate.

In BlueSky or AT Protocol world, as I understand it, the claim is that it is not dependent on one “personal data server” and the other semi-centralized bits could enable the poor users to still migrate elsewhere. I think that is all somewhat theoretical in Bluesy now, as they have just now gotten basic federation working. 

But the question is: in an ActivityPub world, how could we evolve to solve that one admittedly problematic use case — without resorting to centralization, and without any blockchain gobbledegook?

I have some beginnings of ideas but want to see what you all think first.