I am trying to stay out of it - it's a little hard when they both still talk to me, but they both said they're not talking to each other. Mostly, if either of them say something about the other I say 'did you TELL him/her that?'
They struggle, you try to support and encourage communication.
Taking a break to cool off temper is fine. Not speaking ever again is childish. And it will put you in the middle later.
They sound like they need a little cooling off time, that little break thing. Let's all agree to that, and agree when to meet up for the trio talk. Let's deal with this sensibly , mourn the loss of the old config, agree how we all want to be in the new config... and then try to place nice while everyone transitions to this new state of being.
You feel whatever you feel when you feel it. That's natural. So.. feel it and let it blow through. We cannot control feelings.
After that, you can choose. Not just merely "react." But choose to "act" with intention. We CAN control how we behave.
Hang in there!