It's really talked about here. I'm among those who believe he should be that wild card.
But DD won't do it. He won't because he wants guys who play on big teams. He won't because he doesn't like youngsters like that. He won't because (and that one is actually understandable) he'd then have to choose 5 guys out of : Benzema, Giroud, Gignac, Payet, Fekir, Griezmann, Coman, Martial and Ben Arfa.
Benzema is a special case, but if he is eligible, he'll go.
Then you have Coman, Martial, Giroud and Griezmann who will go.
So Dembele will have to beat Payet, Fekir, Gignac, Ben Arfa, Gameiro, Lacazette and potentially Ribery.
Not gonna happen, as much as I'd like him to go. If Benzema doesn't go to the Euros, then he has a long long shot. If Benz goes, then Dembele really doesn't have a spot for him in DD's mind.