I think that Elon is genuinely well meaning, but he is far from understanding the effects of government.
All such a ban could achieve is keep white hats from working on AI. So basically evil AI programmers would get 6 months head start.
https://fortune.com/2023/03/29/elon-musk-apple-steve-wozniak-over-1100-sign-open-letter-6-month-ban-creating-powerful-ai/