Was long gone IMO, i would say as far as at the start of the season. I don't think it is a question. He took a lot of time a couple of years ago to sign a contract and i don't think that he will sign now after seeing what has happened here.
Baffling situation all around. He is much better than Lingard/Pereira/Chong and barely played. Chong was useless most of the time and got chance after chance, a bit of a joke to hold him back due to his size (i can't think of any other reason).
If i was him, i would go to the Bundesliga or Spain, but i have no doubt in my mind if he goes to a club where the manager believes in him, that he will play quite regularly and shine, small or not. You can quote me on that.
I don't think Chelsea is that bad for him, he will fit in with Hudson-Odoi. He is competing with Mount and Barkley for that more advanced central spot, and he will surpass both of them with regular game time.