I suppose this could have some merit to it. But as for people thinking that this is just filler and an excuse for not making a Halo 3 sequel, honestly guys, I don't want a Halo 3 Sequel.
We know that the chief was heading for some planet after freezing himself, and it should be left at that. We do not know if he is dead or alive. This is akin to a sort of "and they lived happily ever after." If you took any fairy tale that ended with the princess getting married, the story ends there, you don't want to go into their post-marital lives and see all of that, since real-life doesn't make good fiction
Making a sequel to Halo 3 would almost compare to MC removing his helmet and looking at the camera. And I swear, if 343 does that, I will renounce my devotion to the game!
But sure, remake the game so it looks prettier, that would be nice, The Captain Keyes in Reach looked pretty bad-ass, along with I want to see some FLOOD-MONS!!