Hi Flying Hawk! The reason is that we do not cover it. We only have forums for the shows that we cover; however, please feel free to discuss the show here in the lounge or any other show!
We only cover a few primetime shows and in addition our Primetime Dish, which is located the latest news room (look for the button on the top bar) has various spoilers for various shows including GOT. It's posted each Thursday morning. :)