Hi @dschnare,
There is still a lot we don’t know about the implications of Sign In with Apple, but from what we’ve seen, the only one of those scenarios that will fall under the mandate for supporting Sign In with Apple to be in the App Store would be those that use social logins. In that case, it seems Apple will require you also support Sign In with Apple. If you’re using Auth0 already, Sign In with Apple can be turned on like any other social connection (you can try our beta to get an idea of what it looks like).
There are some broader implications that we’re taking a look at as well. For example, if someone has an existing account and wants to start using Sign In with Apple, how do you link their Apple account with information in existing accounts if they choose to hide their email? There may be some setups that allow the user to easily connect existing accounts when they first sign in with an Apple - we should have more about this soon on the blog.