The author makes some interesting points, but admits in another post that chat itself is distracting and sucks productivity (to the point where he had to invent "Pomodoro for chat" to break free). It feels like "group chat by default" would be even harder to break away from, especially if you're concerned about missing that serendipitous moment he talks about.

I have to say I do like his Chatodoro concept, however, so perhaps that's the key.