The problem with no notifications is that because you're still in a room where interesting stuff is going on, of course you'll check the chat history and/or join the people already chatting. (Unless you use up willpower not to, but the whole point is using less of that.)

Having a 25 min work + 5 min chat cycle seems to be a good thing though; start working because everyone else went silent is so much easier as going back to the "library" while everyone else is still talking in the lobby. If you're working, don't go there, that's it.