The LLC is separate from Sponge. Its discussions do not belong with the rest, its announcements don't really belong in the Announcements category. The alternative is setting up a separate forum entirely (forums.spongepowered-foundation.org or similar) which we felt unnecessary.
If you don't want to see LLC-related conversations "spamming up" your New tab @ButterDev then you can set this category to Muted. On the category's main listing page click the little O in the top right, and choose Muted from the list.
As for there being only one thread, you have to start with something!