I am even surprised that the Taliban let someone buy the queer.af domain.
But it's also a cool feature of the federation, an instance is closed by an authoritarian government, tons of others are still there, and migration is easy, so you don't loose you whole network. Still an annoyance for the user, but not as much an annoyance as when a centralized social media closes.
Just as an aside: unfortunately some of the Taliban are actually very smart - in an academic sense. Some of them have gone to the best schools and universities our world has to offer… and then decided the dark ages are where we should be. Go figure. But, to clarify, they aren’t all backwards goat herders from the middle of nowhere.
Just because they can take control of the domain doesn't mean they somehow have access to the data any servers that used the domain have. Those servers were, i feel confident, not in Afghanistan. Domains are just redirects, so the Taliban have nothing on any of the users.
If you have control of the domain, you can also get an X.509 certificate from any CA (e.g. for free from LetsEncrypt). Then you can put up a new server on that domain with a valid cert. If that server supports ActivityPub, it can provide new public keys for private keys you control for all users on the server, and can use the corresponding private keys to sign messages from any user on that server to any community those users are still subscribed to. In addition, any users on other servers still posting to / interacting with communities on that server would cause their server to send that to the inbox on the new server.
This means any usernames or communities on queer.af should no longer be trusted.