I don't understand this move either unless it was an emotional response to not winning the frozen four. If his brother is not going to Michigan next season (which I can understand him wanting to play with his brother) then what is the purpose of returning? Further development would not be better there than in the pros. Maybe mom wants him getting his degree? Maybe he places higher importance on the degree than most? It's quite baffling actually and yes, it does sort of mess up the rebuild timeline. If a young, solid second line center is available, I would move him as well because he just put question marks on himself with this decision.