Disagree with pretty much the whole post. Ajax had excellent defence in the early 70's, then in the 90's pretty good one as well. Since the turn of the century gradually the quality of the defence in Holland has decreased - same goes for Feyenord and PSV.
Pass and move tactics aren't really something new to the game or revolutionary from that Ajax side. They are very good technically because that is the focus of the game in the Dutch league, that doesn't mean that tactically they are better than United side especially under Mourinho.
While technically that Ajax side can be very efficient, positionaly and defensively there is a lot to ask for. Most of the young players that were on last night lack the positional awareness and experience which in a cagey game and against better opposition leaves a lot of gaps both in midfield and at the back.
Against Lyon it was quite an open game which played to their style - hence they won it comfortable having also in mind that Lyon attackers were also pretty poor both in finishing and creating chances.
As for Pogba not making it in this Ajax side -