Or he's The Other after all.
I really doubt that Moffat would hang the story of a character on backstory that only about twenty thousand people are going to be aware of.
I don't believe the 8th Doctor was featured in the episode with Clara encountering the incarnations, so wouldn't it have been awesome for the reveal to be HIM?
I believe there are still issues with Universal over footage from the television movie. During the BAFTA tribute, they used a promo image of McGann's Doctor instead of footage from the film.