I think it may be a situation where they either A) don't think they need announce anything or B ) don't think what they have is "worth" such an early announcement. Here's what I mean:
A - The announcements aren't for fans. That should go without saying, but the purpose of the announcement is to drive sales of vacation packages. The AHS announcement (the big get) being so early gets the biggest draw public. Now, if last year saw no real uptick in sales in June then they may choose to save the announcements for July and August when sales likely surge. They may also be relying on VB to push packages so its own marketing isn't "tainted" by HHN (it gives a more accurate view of what works).
B - They've announced AHS. They've announced The Shining. Compared to last year, the rest of the IPs are fairly ho-hum. A Blum-house, as a compilation, is a difficult to "market" entity because it's a jack-of-all-trades/master-of-none. Ash really the Evil Dead is an intentional misdirect for a niche show and can't really market itself as the cult classic status it would benefit from. Saw hasn't had a release trailer or started building any hype. The Originals don't get individual announcements. Aside from acknowledging that the houses exist, there's nothing really screaming out as "huge" from a marketing perspective that really warrants a lot this "far" out.
And the fact that an icon hasn't been announced yet basically confirms it's unlikely a returning character. A new character would get announced in August with the rest of the originals.
The last five years have proven one thing: you can't rely on the previous year for announcement schedule. It's entirely likely we get Evil Dead beginning of July, Saw end of July, Blumhouse beginning of August, everything else August 17th.
Relax and be happy we aren't getting midnight dumps on 31 August anymore.