Like Stackoverflow's meta, or Reddit's /r/announcements. A place where users can discuss, ask questions and file complaints about the forum itself, and its policies and moderation.
Because the mods here are often way overboard enacting inane policies without sense or reason or oversight or justification. They don't educate, inform and adjust, they just have a move/delete hammer, and everything looks like a nail.
Successful, happy, helpful, lively and friendly forums don't move everything that could be vaguely described as a question, image, suggestion or support request to some tiny, dead subforums that nobody reads.
First, it really pisses off the thread creators to have their post moved to oblivion.
Second, it makes the General Discussion forum slow and boring. Most people will miss most interesting suggestions and questions, as it seems it's still the same old threads from yesterday on top.
Third, it creates a toxic environment where most of the threads in General Discussion are complaints, because they're about the only type of message that doesn't get moved. Do you really want new members or prospective customers who check out the forums to only read complaints about the game? I didn't think so.
Finally, you also need to do something about those 3000+ page abominations of dev diary threads. It's insanely long, nobody can read through all that ♥♥♥♥ scouring for relevant information. It's disrespectful to your users.
You should take a hint from Paradoxplaza. They have a weekly fresh new Dev Diary thread which is the main source of new information on the development of each of their games. They come out on fixed days of the week, so the fans have something to look forward to. Also, they have a "show dev comments only" button in every thread to filter out the rabble.
You're welcome.