If it's more of a re-imagining than a remake, I think that'll make more people happy than doing a straight remake with no changes at all. Probably not thinking this through too much, but in that scenario I only imagine the people who want a 100% true make and think that will work well in context of Halo 4's sandbox.
That's actually my hope. The combat sandbox has changed enough that updates will be needed to make the map play well. Rolling with the Valhalla theory:
The map would need to be expanded due to the increased range of weapons and the fact that everyone has sprint.
The bases would need to be updated as players could jetpack/thrust pack in from all angles, rather than from the intended entry points.
And so on. A Sidewinder --> Avalanche type of re-imagining is what I'm hoping for, whatever map it ends up being.