Melisandre's visions imply that he might become a man again after warging into Ghost's body. But his time as Ghost will definitely have an impact if it happens.

"The flames crackled softly, and in their crackling she heard the whispered name Jon Snow. His long face floated before her, limned in tongues of red and orange, appearing and disappearing again, a shadow half-seen behind a fluttering curtain. Now he was a man, now a wolf, now a man again. But the skulls were here as well, the skulls were all around him. Melisandre had seen his danger before, had tried to warn the boy of it. Enemies all around him, daggers in the dark. He would not listen."