Today, October 6th 2021, Apple has issued a release around the timing of the new account deletion policy, which will go into effect on January 31, 2022.
The press release states:
..all apps that allow for account creation must also allow users to initiate deletion of their account from within the app.
https://developer.apple.com/news/?id=mdkbobfo
The relevant passage of App Store Review Guidelines states:
(v) Account Sign-In: If your app doesn’t include significant account-based features, let people use it without a login. If your app supports account creation, you must also offer account deletion within the app…
https://developer.apple.com/app-store/review/guidelines/#data-collection-and-storage
So, all apps on the AppStore must comply with this new requirement shortly after the holiday allowing users to initiate deletion of their accounts from with-in the app to remain in compliance (and thus available on the AppStore).
While this seems a minor change compared to this past spring and App Tracking Transparency, it will certainly assist users who which to assert more control over their data and prevent them from trying to isolate where they can undertake this operation across all of the various touchpoints a brand may use.