[jhanschoo]

Actually, from the article and the rule referenced (https://developer.apple.com/app-store/review/guidelines/#sig...),

the rule seems somewhat orthogonal to developers getting emails. Developers can still request login by the old school email-and-password with (or without) sign-up verification by email. On the other hand, some third-party logins don't give developers their users' contact information (just a token to verify that they're on their platform with no authentication permissions, or a dev can request that this be so else the third-party will inform the user that the dev is requesting their contact info).