Q: Are Dracthyr actual Dragons?
A: Yes.
“We knew with a Dragon themed expansion, we wanted to let you play a Dragon. Not a big Dragon like Alextrasza, but a Draconic Humanoid.” - “They have unique abilities as literally a Dragon”
They are not lesser races with simply draconic features nor are they simply dragon-kin. I can’t imagine anyone who has any kinship, likeness or anything merely ‘akin’ to Dragons translating into the innate biological capability of having the power of all 5 Dragonflights.
Something capable of doing that at that point is just called a Dragon.
“Graham: Even though it’s not a giant screen-filling dragon, it’s all about delivering on the fantasy of being a dragon whilst fighting.”
Jeremy Feasel: “In this particular case, we really wanted to do ‘You can play as a Dragon’. So what is the player version of that? (Where you can play in raids without obstructing everyone’s view with a giant Dragon Form like Alexstrasza)”