No release date has been given for the titles, but Microsoft is changing things up a bit with how the games will be released. Rather than release with every game all at once, Halo: The Master Chief Collection will roll out one game at a time, starting with Halo: Reach. The rest of the series will follow in chronological order.
On Xbox One, Halo: Reach will be released in two parts: The Campaign and Firefight will be available as a premium add-on, while the multiplayer content (which includes Forge and the Theater) will be available as a free update. Xbox Game Pass subscribers will have access to multiplayer without any additional purchases.