They're enjoying the schadenfreude of Dario "AI is so dangerous, we really need to ban and regulate everyone" Amodej getting his models banned by the US government.

They didn't get banned by the government. The government says they they want to track the Identity of everyone who uses it. Same way they track identity when using an airplane.

Dario cried wolf one too many times, the Trump admin believed there was a wolf, and now Anthropic users can't use Mythos or Fable. It is effectively banned until the government says otherwise.

It's a ban until they add ID tracking / face tracking. That is worse than banning it. It is only effectively a ban because so far they refuse to do that.

Jury's still out whether they refuse to do that.

Currently it's just that they can't immediately implement those checks. They'd need some biometric check on API calls and some magical way to prevent the authenticated persons from reselling the service to unauthorized people.