Book 5 spoilers
(SPOILER)Actually it's not all that cut and dry. Personally I think the foreshadowing is that this heavy injury (only two of the stabbings could be considered fatal) is the catalyst for Jon to learn his Warg abilities properly, just as Bran needed his fall and Arya needed the blindness. I think he will then quickly use this to somehow get his physical body repaired (NOT Melisandre hocus pocus) after quite a while, and be able to return. I think there are several possibilities, but like you I think it is unlikely that this is the complete end of Jon, just out of a story perspective and not because I don't want him to die.