cal dropped dod 1.3 because no one was showing up for matches, and TPG had 80%+ for the whole season which was more than twice what cal had. they couldn't really justify having a staff monitor a "dead game" which 1.3 was when they dropped it. they did bring it back (only didn't exist for 1 season) with a complete revamp of the league to get rid of no show clans, and didn't even exceed 30 clans to join the league after that.
anyways, my guess is MGL bought out CAL to eliminate competition not only because cal was the next biggest league host...but MGL (to my understanding) is primarily focused on consoles, so it's 2 birds with 1 stone. do away with leading competitor and competition with a different platform.