For starters i hope we can get the ultra Elites restored in ODST firefight as the seem to be missing in the recent update. I would also love to see the Elite Zelots, (the gold Elites) also apear for more variety.
They need to restore the Elites ability to drive and hijack vehicles as well as restore their ability to get into abandoned vehicles (i also want to see this feature added to the Elite Flood forms) i would add a layer of risk to just book it out in the open as well as punish those that ignore the vehicle at the start.
I believe they once said they were trying to put the Elephant in ODST Firefight, if so i hope the can add it.
I hope to see Equipment get added to ODST Firefight
Moving away from ODST, i hope 343 will finally give the Elites in Reach piece by piece armor customization as well as options in custom games where you can make game modes that usually ignore player preference actually take into account player preference so we can have modes like ctf or odd ball wit a mix of Spartan and Elite players.
I hope the Elite i halo 3 can get some more armor customization that fits the theme of the fractures lime what the Spartans got in Season 8
Finally moving back to Firefight, i hope Reachs Firefight can get a little love too. Like allowing use to spawn other vehicles rather than the Chain or Rocket Warthogs, having the Falcon, Banshee and Scorpion on certain maps would be amazing. Also while probably unlikely, i would love it if either they could make friendly or enemy Covenant in Firefight which would allow you to use your Elite in Firefight and fight along side your Spartan brothers, or have you pitted against traitors of the Great Journey in Firefight Versus. And i wod love the idea of boons to be added to Reachs Firefight aswell.
Finally moving back to ODST, i would love for their to be made night versions of the maps that dont have a night variant, Lost Platoon at night could be fun especially if the Engineers are added to it as well