@Adeptus Retardes I'm a bit ashamed to admit this... but I got into the game not long after quickplay got removed. To be fair, that was like... almost 10 years ago and now I have 700+ hours in the game, but I, alongside many people, simply have no clue what quickplay was like. For contrast, when I started, I was still in middle school and now I'm old enough to pass for a master's degree student.
But it does sound like Valve will inevitably revert matchmaking back to some sort of quickplay system to save on money on running servers and updating their anti-cheat. I mean, they already outsource the creation of any new cosmetics to the community, and with the game's source code publicly available to the community, it could lead to a self-sustaining community that just makes their own game modes and modifications. TF2 has potential to turn into Dwarf Fortress in that sense (no pun intended).