Yeah, and I just don't share that pessimism. I think the advantage this class has over Demon Hunters is a much wider design base to work from. Demon Hunters only had Illidan HotS, since most of their WC3 abilities were already cannibalized by other classes, and frankly Illidan HotS is a very shallow hero in his own right. Also, them coming in as yet another agile Melee DPS/Tank class right after Monks really limited their space even further. It was clear that Blizzard was very concerned about DHs overlapping heavily with Monks, Rogues, and Warlocks so they redesigned all three of those classes in Legion, and brought in the DH in such a "safe" fashion that they didn't even port over the Warlock version of Metamorphosis over to the new class. They instead took the HotS version, which is also melee, and sort of short-circuted one of the cool aspects of the DH gameplay from WC (agile melee fighter turns into massive tanky ranged monster).
This dragon class on the other hand simply doesn't have those types of constraints. Unlike Demon Hunters who only had Illidan HotS as a foundation, this class has Alexstraza, Chromie, and Deathwing HotS along with a multitude of WoW dragons in lore. Also its the first new ranged spec since Vanilla, so there's a lot of concepts that it can draw from without it feeling redundant.
In the end, I think it's going to be fine. We'll get a better idea of course when more abilities and their talent trees are released. Fingers crossed!