March 12's Inside Xbox revealed that The Master Chief Collection is coming to PC as a "rolling release". However, you can keep an eye on Halo Waypoint (and GameRevolution) for further news on Halo MCC.
Instead of bringing all of the Halo games into the PC ecosystem at once, 343 Industries and Microsoft are instead opting for a slower approach, in which each title is released one at a time - this is being done to ensure a stable launch for each title.
Halo: Reach was originally released on Xbox 360 in 2010 and was the final game that developed by Bungie before they moved on to create such titles as Destiny 1 and 2. In terms of content, each individual game will have Campaign, Multiplayer, and Custom Games, as well as Forge and Theater mode.
In our review of Halo: Reach, we said "It's a fitting end to Bungie's involvement with the franchise, one that both references the past and injects new life into a tried and true formula". Additionally, Halo: Reach is also being added to the MCC on Xbox One, and will receive support for 4K HDR and 60 frames per second (FPS) gameplay. In addition to this, the order in which the collection is released will be chronologically, beginning with Halo Reach.
The MCC is coming to PC, but where will you be able to actually enjoy it? The game will arrive on PC via the Microsoft Store and the competing Steam platform, and will be optimized for PC with enhancements and tweaks. The biggest note is that the entirety of the Master Chief Collection won't be released all at once, but in stages.
For Halo 3 and Halo: Reach this will be the first time on PC while Halo 1 and 2 have found their way to PC in the past. But it's not just coming to the Microsoft Store - Halo is coming to Steam, as well. While the MCC used to have some issues, 343 have been patching it consistently since launch, and it sounds like the PC will have some extra icing on the cake.