>>716446852 (OP)
Realistic answer is they would have to uproot a lot of systems they wrote for their newer Casual format. It would break a lot of now existing code and functions that weren't there pre Meet Your Match, like contracts for example. Ultimately they'd be better of developing TF3, or from the ground up TF2 in Source 2, and even then, how worth it would it be implementing Quickplay as we use to know it compared to reimplementing Casual as we know it today? This is ignoring the inherent problems and bugs that came with Meet Your Match and has been bugged since, as well as the Competitive userbase, as small as it is. It's not just a "we should add Quickplay back" as much as "how do other games implement their quick play?" which the answer to the latter is arguably what we have now. And yes, I want Quickplay back too.