So I did an in-depth, quick 4 minutes of web researching, and it looks HalloweenMovies.com, the source of the leak, is owned by Compass International Pictures, a defunct company now owned by Trancas International Films, Inc. They own the rights to Halloween 1, 4, and 5. So it looks like the rights holders were ready to announce, which leads me to think that the hold up is on Universal's side.
Another thing to consider, though, is what the house content will be, and if that's affecting the announcement. Universal owns the rights to Halloween 2 and 3, and Dimension owns the rights to 6 - 10, and any new films. Maybe, if the house is a best of, they're having issues with Dimension? Otherwise, it seems like the rights are all lined up.
I'm of course by no means saying that I think the house has been cancelled or anything, it's just odd that this hasn't been announced yet. Particularly since they went ahead and announced the original content already, and that's been saved for last the past few years.