Even without an eclipse, one can see the full disk of a crescent moon. Only a small portion of the disk is directly illuminated by the Sun, but the rest is illuminated by reflection from the Earth. It would be quite plausible, and in fact, easy, to therefore see the entire disk of the Moon at noon, since a crescent moon is close to the Sun and would therefore be up at noon almost anywhere on the Earth. So I don’t think this is the meaning of the prophecy.
If one is worried about the definition of “noon” at the poles, then just step a few feet away from the pole in any direction. This won’t have any significant effect on what you see in the sky, but it will put you in a single timezone.
And finally, I think that the simplest resolution is that the author just isn’t too up on his astronomy. Tolkien, for instance, seemed to have had the impression that it was rare and noteworthy for the Sun and the Moon to be in the sky at the same time, when this is actually a commonplace occurance, and except during full moon, happens every day.
Somewhat off-topic, but maybe of interest: One of the Harry Potter books claims that Harry observed the planet Venus at midnight, which would seem to be totally impossible. Wish I could find the exact cite, but I remember reading in Sky and Telescope magazine a while back that if the conditions are just right, it can be done from the latitude of the UK.
During a total solar eclipse the back side of the moon is fully illuminated at just one moment in time. This is the instant of the new moon.
The full moon is fully illuminated for just one instant of time, which can be at any time of the day or night local time.
The quote in OP most likely means “It ain’t gonna happen.”
