So I downloaded Reach the other day and I only downloaded it. I never had previously downloaded the MCC on PC, I wanted to play ODST also the same night so I attempted to download the MCC from the store. However it told me that it had been installed. So I booted up Reach (titled MCC) and all other games are missing? It refuses to acknowledge this in the store and when I try click on the games within the launcher nothing happens they are greyed out. I suppose this is similar to the issue with Reach not appearing for other users who have done my task the opposite way around.
Halo Reach is the only game available for now with the remaining titles coming over time through 2020.