The apps cannot track if they have no permission to access the respective APIs that give them data they are tracking. What are they going to send via the network? Only things that the users specifically give to the app.
Look up what the Apple's tracking-prevention policy prevents for users that don't opt-in to tracking. You cannot ban generating device or user identifiers with OS permissions alone. Prevent using the built-in ones, sure, but fingerprinting or otherwise creating device or user IDs to share with 3rd parties and other apps? I'd love to see what a permissions model would look like that could do that automatically, at the OS level. I don't think such a thing exists. Not for any app with enough access to the system to do anything remotely useful in the first place.
