I admit I would be a little sad to see GenDisc go (I look at it when
really bored

) but I agree it shouldn't be effectively the first thing visitors see. I like the idea of making it forum members-only. In the interest of not clogging up new users' view of the forums, I also like the idea of having it in users' ignored boards by default, effectively making it opt-in. (It's in my ignored boards, for example.) Requiring a minimum post count and/or moderator approval to post in GenDisc sounds reasonable or at least worth trying.
Not sure on keeping/removing mod-specific boards, although agreed that having a lot of inactive public boards doesn't look good. It does sound potentially useful to have at least links to campaign release threads, if not the actual threads themselves, all in one place. By links it could be something akind to the "Moved" marker thread that gets added when a moderator moves a thread to another board. Maybe a read-only list of threads, with each thread linking to a campaign's release thread. Perhaps "released campaigns" and "released content" (assets etc.) should be in two separate lists (separate read-only boards?).
ANyway my $0.02.
EDIT: Or since sifting through a board can be a pain, maybe two release threads where each release campaign/content gets its own postlink in the corresponding thread? Another thought. EDIT 2: Or maybe that would actually be more annoying than one thread for each campaign/content item?
EDIT 3: Or maybe two threads where each thread is one big post full of release thread links?