That privacy seems a bit overboard though. This is fine if a user can create his account directly inside the app. But it's not very clear how to support a workflow where you have an organization with multiple users authorized by an admin to use the app. How can the admin add a user to his organization, if he doesn't know in advance the user randomly generated email? I guess you could send an invitation code, and let the user enter that code after the apple sign in, to associate the account to the authorized user. This sounds more complex for the user than a workflow where the admin can directly authorize specific emails.