To be honest I really emphasize on the talk show part because it was the heart of Graal Radio.
I checked the World Chat thing and it seems awkward and clunky. One advantage of having a radio is that you are still able to play and do things while listening to it. And another thing is that they can form new or expand circle of friends.
At first you made it unclear and I thought you meant group chatting through a radio. And I would've said "That's what the gang chat is for", but only if you were to, hypothetically, say that. But talk shows? That's more like it!