Only Janos Slynt and Alliser Thorne think Jon is a turncloak now. Everyone else thinks he's a hero for capturing the Big Horn, even though mainly he was hiding in a tent delivering a baby. This is the kind of stuff that happens when you're a character in a GRRM book.
He's summoned to meet Stannis. So Melisandre is still about, but so is Davos. It was Maester Aemon's letter he read in his last chapter, and that's why Stannis is here. I like this line from Stannis, which is really what Davos had told him: "I was trying to win the thronse to save the kingdom, when I should have been trying to save the kingdom to win the throne." Which does sound like excellent advice, and also the sort of honourable behaviour that won't go unpunished in a GRRM book. We'll see...
Anyway, Stannis has an interesting offer for Jon: Bend the knee, marry Val, and he'll remove the taint of bastardy to make Jon a Stark and install him as lord of Winterfell. I don't know how that works with the Night's Watch vows but since Stannis has just won them a major battle and saved them from total destruction they'll probably go along with it, though Alliser Thorne won't be happy. The marrying Val bit is a bit odd but Stannis also plans to let the wildlings settle the Gift south of the wall, and it's a way to keep them in check. In theory, since the Free Folk are free and do whatever they want. But marrying Val doesn't seem so bad; she's pretty reasonable. And Jon does want Winterfell. So he'll probably go for it. Or he might be all angsty and heartwrenchingly deny himself the chance of happiness and/or greatness for romantic ideas about loyalty to the watch.