Yes Rensi,
It is a really wonderful experience as a past learner as well. It is a truly meaningful and effective orchestration. I find some valuable benefits of this orchestration of involving alumni in discussion forum;
1. reducing the workload of the course instructor
2. making the learners feel relaxed
3. enabling learners to feel free to ask queries, put comments, discuss the issues with ease.
4. presenting a novel dimension about looking towards the course from a third perspective.
5. fostering new ideas and suggestions for the further versions of LCM.