Frankie stated during one of the interviews that the versions of the games are post patch... basically the games as they were at the end of their life cycle.
This probably means no easy swordflying in Halo 2 A, which is disappointing.
IMO the campaign should have all the non-game breaking glitches*. That was half the reason I kept playing Halo 2's campaign years after release, something which did not occur with the recent iterations Halo:Reach and Halo 4; they were too polished :/
Glitches in the campaign are half the fun. We're still finding new ones in Halo 2.
* e.g. Regret not dying glitch.
I wonder if the front half rising function for Ghosts/Spectres still exists...