Does an Administrator need a reminder about other roles?

I'm working on a UI where a site Admin can add another user role. In the mean time, we're calling this new role, "Collaborator".

The Collaborator is typically a freelancer the Admin adds to help manage their site.

Does the Admin need to be reminded that at some point, they have added a Collaborator? Just in case they need to remove this person/freelancer (for security purposes) and had forgotten to do so?