Musk didn’t invent the idea of using multiple share classes to ensure the founder(s) retain control of the company, see Rupert Murdoch, Google, Facebook, etc

From the regulators’ perspective: it is a risk, but you disclosed that risk in the prospectus that buyers are assumed to have read (what percentage ever actually do?), hence it is fine

Well, when you buy into an IPO, they make you sign to say you read it. So either you did, or you made a false statement on a legal document