That thread is basically like a bunch of guys sitting around a campfire, talking about Hill-style bows and shooting them, showing pictures of their bows and hunts, and generally just having a conversation. Like any conversation, the specific topics vary, but, in general, the theme has remained focused around the Hill-style bow.
The participants are of varied skill and knowledge, and many are excellent bowyers, which provides some useful insight. It is by no means a closed group, and anyone is welcomed to join in. I don't think you have to read the whole thread to contribute, as most of the current conversations are pretty recent, maybe only a page or two old. Just make sure to use the search function to make sure any new question hasn't already been answered.