What if a user enables Advanced Data Protection (end to end encryption of everything stored on iCloud) on their Apple devices? How much does that change things?
The lawsuit is complaining about data Apple gets when the user uses the App Store, Apple Music, Apple TV, and similar. E.g., when you buy an app from Apple's app store, Apple knows which app you bought, how much you paid for it, and how you paid for it.
That's data that Apple is getting because it is necessary in order to provide the service you are using.