I spent September to November living in French West Africa. Over there, Ligue 1, and not the Premier League, is the main show. I must've watched about 6 PSG games in that period. Rabiot must've played about 3 of those games, and while he was solid, he barely stood out as the next big thing. Meanwhile, the regulars there were something to pleasure oneself to - especially Verratti and Matuidi. Verratti has missed about a third of this season's games, but has always looked otherworldly when playing.
My sense right now is that Rabiot is mainly hype. The potential evidently is there, but he's not going to come in and elevate our starting 11 immediately.