I understand there's a possibility of him surprising everyone but it's not very probable IMO. Players could be less than known and then suddenly step up in senior teams but think of the examples brought up. Pep is the one who gave trust to Busquets/Pedro despite them not being well known academy stars. He also brought up Tello, Cuenca, etc. from the academy and showed their ability on the highest stage. This season Deulofeu who was the star of our B team got barely 2-3 games. Roberto most likely won't get the adequate game time to develop much from where he is now. I don't think he shows any real quality that sets him apart and would give him the edge in the fight for playing time against Song, Cesc, Xavi, Iniesta, etc.
If he were to be more ambitious, he'd request the loan and impress there so he actually has the chance to compare against his seniors for playing time.