I like to think that Geo Descent Labs from Terra Swoop Force (and the two prequels) is behind MCC and MCC Island. Maybe canonically, it's similar to Portal, where Aperture is studying the participants. The machines keeping the MCC lobby afloat really add to this theory, because they seem very technical.
On the timeline, this could take place as a prequel to TSF, or potentially, the lobby is currently afloat above the ice age apocalypse. Some games like Ace Race could even exist to test the capacity of the participant test suits. I mean, a level of Terra Swoop Force has even been one of the TGTTOSAWAF rounds!
This theory works kind of similarly to the Pixar Theory, where it might not be 100% true, but it's definitely more fun to...