I have almost no knowledge on Pedro. Is he really not the type of game changing player van Gaal was on about, or is he just being vastly underrated on the caf - perhaps in the shadow of Messi, Neymar, Iniesta etc.,?
The best way I would personally actually describe him is a sort of Reus/Muller/Walcott hybrid. He's extremely hard working, direct, very fast, a good finisher, excellent movement with good technique/dribbling from wide areas and he creates a good amount of chances for his teammates. He is not as good as Reus/Muller, but he's a much better player than Walcott. He will suit a direct counter attacking system well, but he's also intelligent enough to work in a possession system with his great movement and link up play (obviously - he was part of Pep's tiki taka).
Individually, he is not that type of "game changer" LvG was talking about, but his effect on the team could be more profound. i.e. along the lines of "sum of the parts is greater than the indivduals etc" because his role could be exactly what we're missing, and what we need to bring the best out of our other players - Mata/Herrera etc. He will keep the width and provide a "better" balance, with a pacey outlet on the wing.
He hasn't been a first team regular since Barca signed Neymar though. Alexis was preferred to him 2 seasons ago (who himself wasn't that great!), and now obviously, Suarez. But if he regains his confidence and form with more playing time, he'd be a steal at 20-22m pounds, IMO. A lineup of:
-----------Schneirderlin----Schwein/Carrick
---------------------Herrera/Mata
Pedro--------------Rooney--------------Depay
would be excellent IMO. But I'm not sure what LvG's thinking is.