It has been a while since I watched Barca B, since in most cases I used to download it from youtube after the game and watch it later but that is no longer a possibility.
I watched his highlights, and he absolutely looked like a CM there.
I feel a bit worried about it because he is a project in that position and it seems we are rushing things with him. I am starting to think he might have been better if he stayed at Juvenil team to learn the craft, although as a footballer he is too good for that.
I won't be surprised if he ended up being back to CM, just like we did with Xavi himself and Wenger with Cesc (both were CDM in the academy)
He has this thing, probably due to his similar structure, where he passes the ball and kind of hops into space, where he looks like Busquets.
I wonder if this likeness bias is what pushes us to try him at defensive midfield.
He is a smart player though, and has more chances of learning the position than Nico (Id say his natural scope of quick passing and awareness is superior to Nico).
A few have said on the forum, and it doesn't seem we will go that direction now, but Cubarsi is probably the best candidate for DMC we have. By far the best understanding of positioning and reading of the game that I have seen. Excellent quick distribution. And naturally defensively orientated.
He would be more Rodri than Busquets, but that isn't a bad thing in modern football.