They would need to implement voice channels and they can't currently scale the gameplay right now. Given most games that even have voice chat, have everyone just use Discord anyway because you need the matchmaking OUTSIDE the game in the firstplace.
Some kind of plugin for Discord/Teams/Slack would probably be the easiest solution.
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.
