If you surrender now I MIGHT let you live.
Bungie probably doesn't update Halo 3 anymore for a few reasons. As far as I know there will never be any more DLC for it, and so there is no more money to be made, and if they did actually improve Halo 3 matchmaking with an update, there is a good possibility that people would leave Reach in favor of Halo 3, and dwindle Reach's population down even further.
I'm in complete support of a Halo 3 update, and think your ideas would be great improvements Shieldypoo, but sadly I don't see it happening.