Profile-driven User Enrollment was deprecated last year, and support for it has been removed in this year's developer seeds of Apple OSes. Devices that were already enrolled will continue to work, but it is not be possible to initiate new profile-driven User Enrollments in those OSes.
To be clear, account-driven User Enrollment, profile-driven device enrollment, account-driven device enrollment, and all other MDM enrollment types are unaffected and continue to be supported.