Mick's post match interview gave further clues about what is to come next season. He was very clear that he sees Williams (new contract surely guaranteed) and Colwill playing the Harry Wilson role - and he will not be prioritising that position in the summer window.
Playing Pack in the back three - with all the caveats about not being tested that you gave - shows that he knows the lack of passing accuracy and comfort in possession has been a problem. If Pack drops back permanently (hopefully not a sign that Mick expects there to be serious interest in Morrison) that may give him the opportunity to do something in central midfield?
It is disappointing that none of the u23 subs got on the pitch, but I think Mick is genuine about wanting to give youth players a chance. At least I feel more confident that some of them will make it under him than under the previous two managers or Slade (Paul Trollope might have been good for youth too if he had survived). This season we have seen serious pitch time for Bagan, Harris, Sang, Brown and Colwill - with only Brown having proper first team experience on loan. Half a dozen others have been on the bench, and the whole u23 squad has been training with the first team on a regular basis. That is a transformation.