Despite the implication of malice that other comments seem to be directing at Microsoft, this just seems like a bit of an oversight (i.e. inexperience) on behalf of the school’s IT team. Nonetheless, I would have expected MS to ensure that the process includes clearer guidance for the account owner, and for deliberate decisions to be made by the school to enable this type of action. They did a very good job of provid…
That is a personal account shouldn't even be possibly converted into an AzureAD one: if you want it's another account, with another email and another password. This possibility of mistake should never happen.