From talking to parents involved that's a bit harsh. They were competitive enough u15 and u16. The one criticism I hear again and again though is that he got fixed on who his best players were, and what their positions were, very far out (as in at u15). I was told of several kids who were backs in JMs set up, and never really tried anywhere else, who were cut loose ultimately and then looked good in the (admittedly lower standard) Celtic Challenge as forwards. But no one doubts his commitment tbf and I'd say he is genuinely devastated the way it worked out, as are the kids themselves and the parents. It's some time commitment by them all.
He shouldn't get u20s though IMHO, time for someone new to look at this age group afresh in a couple of years time.