I completely agree with the reasoning for disabling chatrooms but axing this feature also means that normal users are now unable create tours with custom rules. Perhaps a solution would be to allow users to create a chatroom that does not anyone in them to send messages? the most intuitive way to implement this I think would be to revert mgc to what it was but give an alert in chat that says something like "because you are not gvoice/room driver, sending messages is disabled."