Voice Chat should be expanded to cover the whole team.
Honestly, I can't think of a reason not to do this.
Mic spammers are annoying, but that's what the mute button is for.
People can be toxic, but when that happens it's almost always going to be in the text chat. Hell, even if somebody is toxic, that's what the mute button is for.
It'll make communication much easier, making it easier to coordinate with strangers since you can talk to them.
You don't even need to add anything new. You have voice chat already, just put everybody in the same call if they choose to opt into voice chat.