Key rotation doesn’t automatically include subkeys. The above proposal only solves for key rotation and it solves it with a soft solution that doesn’t require widespread adoption either from users or clients and is backward compatible. It defaults to separate identites for each npub, as they are now. A DVM could serve all the required data checks to clients and relays, so they are not required to run extra services or complete implementations for themselves.

I don’t have an equal solution for subkeys.