MMR and DBD
I'll keep it short and simple
MMR is going to kill this game, a prime example should be a recent release, Black ops Cold War
Since that game is basically constant comp matches, barely anyone has fun and everyone's stuck either tryharding, playing Zombies or quitting entirely. And CW doesn't even have bad balancing for the most part and that's just a shooter game.
Now apply this to DBD, the game would be dead in weeks. Please don't add MMR, I beg, make newer accounts have like, separate queues that go back to normal rank queues after ~5 minutes. If you want to make the game more player friendly, don't just consider the new audience, remember you still have an existing audience to take care of. Even if your MMR works perfectly, the game would become so competitive it'd become a draught of players very quick.
I love this game, please don't implement MMR, improve ranks and emblems, please