What part of "It's right there on the Horde web page" is unclear? It's VERY visible. Where else would you be going, given their front page is just links to other content such as the Horde page? It's also on their Twitter, and their Facebook page, and at all RPG news sites, and on their forums. I mean really, they hit pretty much every forum they have to communicate this, and you seem to be the only one I've seen who was not aware of it.
I was out getting my PHB when it was announced.
The tweet is miles down my feed. I had to search the D&D account to see the actual tweet. Twitter is terribly temporary, and not a good way to handle news.
I only use Facebook for posting pictures of my son for his grandparents and don't look up WotC there.
It's not on the front page of ENWorld, nor a news article on the WotC site.
And I seldom look up the product page for products, especially ones I might have just purchased. I went to the
front page, the
digital resources page, and the
news page and saw nothing.
Had I not come to the forum to see if there was news on the Basic rules update, I likely wouldn't have heard there was a Horde document.
Again, you seem to be the only one with this complaint that they didn't know about the supplement - that seems to be the minority here. That news is in pretty much any place you'd go to look for news on that product.
Except the news page of the WotC site. Or even in the story section for
Tyranny of Dragons.
In two weeks the news articles will be buried by new tweets and status updates, and someone getting the book from Amazon or a box store will have no idea where to get the monsters they need.
Of course, the
Tyranny of Dragons page would have to acknowledge the existence of the adventures and TTRPG for that to work...
--edit--
And I'm hardly the only while. While writing this, a new thread appeared asking about the monsters.
Of the people posting at ENWorld, today, and talking about the adventure I may have been among the uninformed minority. But among actual players and DMs of the game... Maybe 5% of gamers comes to the forums.