They're configurable. In our Xmas party house the entire kitchen is one broadcast domain, like the kitchen at a party. But in the local pub we built for Friday evenings we have "booths" and you must sit down in the booth to talk to people in that booth. By default it's just proximity, so like a real pub there were always two or three girls in the toilets having presumably a private chat.

So you do need somebody technical to make the space work how you need, and if your users are all non-technical you probably only want one type of rule everywhere or it'll confuse them.