Which used to offer both social sign-up (FB and Google) and a traditional email sign-up option
You probably don't know that in this case, Groups was also forced to include AppleID or risk being removed from the App Store
Removing all social logins from this point to ensure compliance would have definitely affected all users who had originally signed in with FB/Google, way before AppleID ever existed
Yet it would have been more consistent! What is the point of going to war against Apple while embracing the private-data-broker model at the same time?
Just send a warning e-mail requiring password change because you decided to remove all social login as a protest.
And provide a password reset mechanism for formerly social-login users that haven't defined a password in time.
That would have been a true act of resistance.
Apple decided to prioritise users over developers here.
As a user, I am very satisfied that Apple made this a requirement.
As a developer, I just implemented it without throwing a tantrum.