IAppleIDCredential.User now returning email instead of unique id?

[cimved]

Does IAppleIDCredential.User now return the users email?

We are using that value as the primary key for users' records on a database and it used to be a bunch of random numbers and letters (something like 001578.33c036e53db24de6b4a07c6b524c625b.3570).

I just checked the database, and strangely some new users' records now have an email as the primary key.

Did anything change? Is it normal for IAppleIDCredential.User to return the user's email now?