No according to Blizzard they aren't dragons. In the lore we got chromatic dragons which are real dragons that were created from multiple flights. Dracthyr were created from mortals because Deathwing thought that the other dragonoids/dragonkin were not adaptable enough. It doesn't say anything about him wanting a new type of dragon. He wanted soldiers.
What powers of chromatic dragons do they have? Wing buffet? Well birds and other winged beings in wow use the skill too. I guess that means parrots are dragons also lol.
No people wanted actual dragons. People wanted actual dragonoids too but they fucked us over on those as well. And no dracthyr do not transform into a mortal. They can take a mortal like form but they can't take a mortal form. You can't be a blood elf, you can't be a human,you can't be a tauren, you can't be any actual race in wow other than the dracthyr visage form.