Yeah, but there's a lot of people that can play dirty, ruining the game experience
I've thought extensively about Discord, and it doesn't work as far as allowing imposters to talk during the round. It would automate the dead/in-round muting, but that's only a small portion of the dope stuff.
Also, I've implemented live chat in Unity before, it's not really that hard. It's more network intensive but not really hard at all.