Barto just said this week that Dembele is staying.
I do hope he is staying, as he is just a great young player and talent.
But I've spent enough time among football players to see, know and feel, that he would also need the presently lacking confidence of the coach and perhaps even more importantly the confidence of Messi and maybe other elders.
In small teams there is always a young "Benjamin", who is good, talented but the elders seem to pick on him, regardless what happens. In Barca it seems it is Dembele at the moment. The coach doesn't trust him and Messi all the time feels he needs to educate him on the pitch. (Which he never did to "talents" like Gomes, Arda, or even Deloufeu or Munir).
By these two factors, you can easily see and notice that the young lad has lost almost all his remaining confidence, often turns back and makes meaningless back-passes, just because he is scared to enter into creative solutions. He looks bogglerish and chicken-hearted.
This guy is mentally destroyed by the team and coach, so it is a miracle he can perform on the level he did today, with a tiny bit more confidence than usually.
Right at the time he got seriously injured in the beginning of the season, his starter place and status was not questionable, although he didn't always play quite well but played creatively and confidently at least. The very injury of his was the result of a very unexpected and creative move.
If he wants to go, that would be a very understandable wish on his part, knowing his situation, but I truly hope he does stay and somehow gets the confidence of this stern and smile-less coach, who made mistake upon mistake this season, but fortunately for him, the qualities of his players did better than he did, that's why he doesn't have to leave - unlike it happened to him at Villareal, where he was kicked out just after six months.
Dembele's future is in the hands of the team and management, so I hope there are at least 'some' folks there with the minimal pedagogical sense...