You can make a proposal of how it would be done, and devs can tell you if it work or not. From my understanding as a dev, it wont be possible to "delete" accounts, best you can do it switch to a new npub, announce it publicly in the protocol and somehow (web of trust or other nip) your followers will follow the new npub and the old one is just ignored by your web of trust.  

 That’s what Pablo already proposed with a PoW implementation