I don't know how many book readers picked up on it, but folks are frequently playing a board game called "Snakes and Foxes" with what are referred to as odd rules. It seemed obvious to me that the game had to come from someone's historical visit to the land of the Finn.

Since the white walkers exist because of magic, I suspect they are somehow attuned to it. Jon died and was brought back to life through magic. I always thought the Night King felt that oddity about Jon, and gave him a wide berth because of it.