With these changes, your course units restricted to verified track learners will be hidden for all students (because groups will be removed, but course blocks will persist with their restriction rules).
Staff will see these units anyway. Additionally, the studio will not indicate which units have legacy restrictions for enrollment tracks (I mean you will not see a visibility restriction message below the unit).
This could be possibly solved by adding a management command to remove enrollment track restrictions from units.
Do you have any suggestions on what steps could ease your catalog adaptation to the enrollment_track removal?