Exactly. He made an impact in his first few games, and then coaches and players worked him out. How he reacts to that will determine how good a player he becomes. If he can work out how to handle two-man marking and full backs trying to keep him out wide, then he can undoubtedly go on to bigger and better things.
If not, then he might struggle.
That's why I think he'd have benefited from another season of first team football with us. You can't beat playing against first team defenders in competitive games to gain that kind of experience.