There should be a distinction between course admins and the rest of the course members. When districts need to hide the members lists from parents and students, they still need to be able to keep course admins available. Obviously, for K-12, the teacher of any course should be known to the parents of the kids in that course, but there are a myriad of reasons districts would want to keep the roster unavailable to parents/students. Keeping the admins available while hiding the rest of the roster seems an obvious solution.
Distinction between course admins and members