Bringing up the prophecy right now won't be a good thing. He will, however, definitively bring it up once they find their bearings. That's the least he can do because, to be honest, he has no idea what to do.

Lady Lunafreya... Ignis doubts that such wound would heal. Passing of time might only ease it ever so slightly but it will always remain open.

"...I'm sorry. By the time I, we, arrived, Lady Lunafreya had already passed." There is a pause where he ponders if he should bring up Ravus. Noct was passed out so he doesn't know.