I viewed it the other way in that in my view it allowed him to get too "free" in his play and at times more interested in doing tricks/flicks even when not required to continue the move. My worry would be that it would have been easier to teach him when young than break "bad" habits ,in the context of playing CM , a few years later. Like you i think it fairly likely we will find out next season. PS i truly hope he has an absolute blinder today .
I agree that particularly last year he got a bit caught up in that kind of lark, taking one touch too many at times and maybe trying a bit too much. He's cut down on that this year and don't think he'll have an issue knuckling down to a pretty serious responsibility, basically shouldering a lot of the Eriksen creative burden (alongside 'New CM') while still playing his own role and contributing more around the park.
That is my view ,and why i thought he would probably have been better staying there to learn his craft , in that he has the attributes to be be both the creative link and pretty much a box to box MF.