That sounds pretty convincing, but I have absolutely no doubt that D&D and GRRM would purposefully keep the fate of Jon Snow secret to everybody, including Kit, just to make sure it doesn't get out. It's one of the biggest uncertainties of the books as they currently stand, and I'm sure nobody wants that little nugget to be leaked. I'm sure they knew *everybody* would be interviewing Kit this offseason wondering if he'll be back, and this would be the way to ensure nobody finds out.
Of course, it's possible that he doesn't come back next season, but the season after that...?
There's too much foreshadowing of Jon Snow's importance for him to just be gone for good. Perhaps, as others have suggested, he may return in a different form...
That jump was basically an adaptation of a similar scene from the books, involving Reek and a different character.
My sense is that they were trying to show her realizing that her interpretations of the visions from the fire were all wrong...and that she may now realize they were about Jon Snow, not Stannis...