MB as an MLS coach isn't ridiculous. MB as a rookie coach with his dad as his boss is.

Historically having a green coach with an experienced coach above him as director of football, GM, board member etc does not work well. Let alone when its yer owl lad. Wilf McGuinness wasn't successful at United as Busby was always overlooking him. Rangnick at the RB clubs was instantly linked with taking over as coach anytime a Leipzig or Salzburg coach struggled. I know I'm forgetting loads of England in the 90's. Hell we had an example here with Mariner and Winter.

MB joining his Dad as player/assistant coach is much more likely.