probably MCC, but ya never know.
It won’t be part of either - it will be its own game
Just as the Insider version for Halo: The Master Chief Collection is separate from the actual game, the Insider version for Halo: Infinite will be separate.
It will be neither after you get a notification via email you will have to download its own seperate thing.
As others have stated I’m assuming it will launch its own separate thing as they are using a completely new engine and whatnot and it wouldn’t make sense imo to use one of the other games as a launcher.
Infinite flighting has nothing to do with Halo 5 or MCC, nor will it or the final game be tied to those games in any way. Infinite and the flight builds are their own separate thing, built on a brand new Engine - Slipspace.
It’ll be separate. They did the same thing for the halo 5 beta and so to with the MCC flighting system.