Blizzard bombarded us with information without any access to a demo or beta. The most heavily promoted thing we know for sure about Mercenaries are those pricey pre-orders. Monetisation is fine in a free game, but when that's what you put your emphasis on, gamers (that were already complaining about prices earlier this year because of battle passes) are not going to trust you.
I want to be excited for a new mode, I want to be able to enjoy hearthstone without having to worry about skinner-box bullshit. Blizzard just mangled this announcement.
They should have built a working demo or beta, released it, and then the pre-orders after a week or so. It certainly might've prevented people from worrying about hearthstone turning into Raid Shadow Legends...which it still might do.