The biggest glaring flaw with Halo Master Chief Collection.....

[Barozi]

there isn't that much Master Chief in Halo Reach. Maybe there's gonna be some repack in the future. Halo Reach, Halo 3 ODST, Halo Wars and Halo Spartan Assault.
They will call it: Halo Random Collection

Maybe also throw in Halo Legends and Halo 4 Forward unto Dawn while they're at it.