They use a term "privatized records" that is not directly recognized by the GDPR. If this is equivalent to data anonymization or pseudonymization is a mathematical proof, that I'm not familiar with. Still kudos to Apple for doing "something", then it remains to be seen how well it stands the test of time.
Not sure but from what it reads like, Apple's servers won't be holding data subject PII and data subjects have choice to opt-in or out. Though this process may need to be may need to be easier to toggle.