It obviously makes good business sense to acquire the best young talents, for small fees or compensation, Hannibal aside of course! But as other posters have pointed out it's not really anything new to Man United. I remember when we signed Andreas Pereira and the hype around him at the time was unreal. I think we can all see that just because a player is sought after at 16 by the top clubs in Europe, doesn't necessarily mean that they'll turn into top class players.
I'm not meaning to have a dig at Pereira either I just used him as an example of teenage superstar Vs the reality of what he is now, which is an average footballer who has no business being at United.