The launch of Halo: The Master Chief Collection was a bit of a struggle for 343 Studios with numerous match making issues at launch.
343 Studios, as a way to apologise for the rough launch are in the process of remastering Relic from Halo 2 and Halo 3: ODST. ODST will be free to those who own the Halo: The Master Chief Collection and have played between 11.11.14 through to 12.19.14. The game is to be upgraded to 1080p at 60fps. Additionally, those who rode the storm will get 1-month of Xbox Live Gold, an exclusive in-game nameplate and avatar. These free items will be available from as soon as mid-January 2015 and will be delivered as codes direct to your Xbox One Messaging Center, so keep an eye on your messages for their arrival.
Both Relic and Halo 3: ODST have a release schedule of Spring of 2015 and you’ll need your copy of the game to access ODST at launch.
There is currently no information about whether ODST will be sold separately to those who didn’t qualify for the free access at this time.