Thanks for the response. I understand, and think that would be the ideal situation; where those who have completed the course move into a mentor role. However, it would be nice for there to be some kind of symbolic reinforcement of that role shift in the interface. Otherwise, it feels to me like the lack of closure precludes one from acquiring a mentorship mindset.
When one achieves a badge, they are then listed as an expert. This is what I mean by "symbolic reinforcement". Seeing one's name in that list symbolically allows the person to shift the view of themself from student to teacher. So, perhaps something similar could be implemented with courses, to better promote the idea of mentorship. Perhaps not calling such ones "Experts", but rather "Course Mentors".
Anyway, it is just an idea.