To start, Van Houten summarized some of the interaction Melisandre had with Jon over the course of the season. “You’ve seen her clock Jon Snow, which is a great ending because you think, ‘Uh oh, what’s going to happen there?’” she said. “You feel that she is concentrating more and more towards Jon Snow … there are slight hints that something’s going to happen.”
In addition to their final meeting, we shouldn’t forget that Melisandre made a blatant sexual overture toward Jon back in “Sons of the Harpy,” presumably because she wanted to give birth to another shadow baby. So yes, the show has established that she’s interested in the guy.
But is she interested enough, and does she have enough power, to try and resurrect him? If the producers are planning something like that, they’re keeping very tight-lipped about it, which is only to be expected. Also, Van Houten obviously isn’t going to spoil anything, not unless she wants to really tick off her employers. She did, however, let slip a little hint about something coming in Season 6.
"I was doing ADR the other day and then the producer was there and he was saying something that I’ve heard before, which is quite spectacular, for next year, which I really can’t say anything about."
ADR, for those who aren’t aware, stands for “automated dialogue replacement,” and involves an actor coming in to rerecord and synchronize her lines, something that happens often on Game of Thrones. Van Houten’s claim that a producer talked about something “quite spectacular” coming “next year” is incredibly vague, and could be referring to almost anything—who’s to say that this spectacular something even has anything to do with Melisandre?