Although Deadpool was tricked into believing that his looks could be restored, is there still any hope of fixing it?
Ways Deadpool's face has been fixed:
Removed the super-cancer and healing factor at the same time. Also did not end well. Technically died.
Reducing the healing factor allows the super cancer to take over and slowly kill him. Reduce the cancer, the healing factor over compensates and kills him. Deadpool's face is a result of an never ending battle between healing factor and super-cancer, and normally changes often, not just a permanent scar.
As in any comic book character, and movie, it all depends on whatever magical cure, or magical cure they come up with. Yes they can fix the face, if they wanted to, for plot reasons. But the established character needs the scarred face to be who he is.
Ajax Francis says there is no hope, that isn't the final word. The movie production team can change that if they want.
See Why doesn't Deadpool's healing ability heal his skin? for more info.