Earlier quoted context omitted.
Therefore, anyone offering Facebook/Google login will also have to accept Apple's anonymized forwarded email addresses, like fc452bd5ea@privaterelay.appleid.com.
But this explicitly doesn’t work as an SSO. How can I tie that back to the actual email address they would have used to create an account using their FB / Google account? This sounds like a tremendous headache that I really don’t want to worry about. But Apple is looking to leverage their power in the app market to force me to implement a tool I may not be interested in as a merchant? I despise being strong armed. I…
However, I wish email and sms would go away as a way to authenticate. Until it does I will be using foo+aliashere@gmail.com so that my account can’t get transferred to someone else through socially engineering a tired rep.