I think they should, as long as they use they do the same to the multiplayer as well as the campaign, unlike Halo CEA. The reason I don't like Halo CEA is because they updated half the game and decided not to do the multiplayer. It doesn't seem complete as a game and also you can get ALL the anniversary maps (incl. Firefight) for Halo Reach for $15, which sort of means you pay for a very expensive campaign.
It would be a good idea to do Halo 2 HD remake, if they remake the full game and update Halo 2's multiplayer, rather than using another game's one.