He's not a #10 and never will be. He's played further back before and done very well.
IMO, RB is going to need a club that sacrifices one of the two cm spots to a player who gets on the ball and carries it, and is tasked purely with that. Only a CL elite club allows that and that's where he'll end up. A team that has a world class defensive midfield partner and is solid and fluid enough to accommodate RB trying to dominate games in dangerous (for his own team) territory.
There will be no shortage of offers for him.
There will be a shortage of offers because he won't be put up for sale.
I agree I think we may see the best of him when moved back, but both Barry and Gueye have been key to our early season form. IMO, the solution is a flat three in midfield, but I'm not the manager.