I'd be surprised if it were a different key from the regular host key.
Most SSH clients I know show a big and often non-overridable warning in case of a changed host key and don't allow (at least not TOFU-style) trusting two keys.
> Most SSH clients I know show a big and often non-overridable warning in case of a changed host key and don't allow (at least not TOFU-style) trusting two keys.
You can solve this with HostKeyAlias, but yeah I doubt Apple would do this. Considering other comments mentioning "just SSHing after reboot" it's certainly the same host key.
Most SSH clients I know show a big and often non-overridable warning in case of a changed host key and don't allow (at least not TOFU-style) trusting two keys.