I would write that the witch brings John Snow’s body back but his soul is long gone. Had a feeling he would get knifed sometime with the foreshadowing in third episode of season one. They will need a bad guy now. They have killed most all bad dogs. I keep waiting for Danerys to turn. She does got dragon blood.
Melisandre could bring Jon back, and because he was “dead” (however briefly), he would no longer be bound by his vows to the Night’s Watch. Even if he is brought back, what would his next move be?