Pc mcc wasn't the full mcc?I'm surprised you didn't know.
No. They launched with only Halo Reach in the PC MCC last December.
They added Halo 1 in March.
Still waiting on Halo 3, ODST, and 4 to release on PC.
If you buy it, each game is separately downloadable. (Although of course, most of it isn't available for download yet).