I heard about this from artist Pia Guerra: "Dungeons & Dragons live @RioTheatre tonight was a great show! Moar!"
So I looked it up.
I've seen kinda-similar improv-and-theatresports-people-do-generic-gaming before (in New Zealand) but that was just a twenty minute thing, and not advertised so in-your-face-look-it's-D&D.
See, I've acted, I've presented, and obviously I've played and GMed (although never DMed, call me a DM like it's interchangeable and I will Tut Disapprovingly) but I ge a bit antsy about having spectators at games. That said, I suppose my antsiness increases with how involved and absorbing a game is. If it's a casual dungeon bash I'm less likely to mind. So... huh. I dunno.