If he does great things in coaching, it will probably be on the HS level, at least until his sons graduate. I really think this Dude wants to follow in his Dad's footsteps and coach his own sons in football. I think his decision to retire boils down to him wanting to get started on that phase of his life.
And I am not BSing about this, this literally brings tears to my eyes right now. What a beautiful friggin idea. (Got two Middle School sons BTW)