You could literally apply that broad classification to any melee class in the game.
DKs, Paladins and Demon Hunters are also types of warriors. Undead Warrior, Holy Warrior, Demonically-empowered Warrior. This doesn't automatically equate them to being the Warrior class.
Talents support the core class identity, not split them off into something completely different.talents are supposed to do just change, change how a class is played, they don't need to be groundbreaking neither too powerful, just resemble the archetype.
Same can be said of talents that try to make a Hunter into a Dark Ranger. You can give a Hunter Black Arrow and Silencing Arrow and Shadow Dagger, but it's still gonna be a Hunter with some necromantic talents, and it's not gonna feel any different from how Covenants or past expansions give you shadow-based, necromantic abilities. You're still a Hunter with a Hunter kit. Same can be said of Warlocks with Metamorphosis and Dark Apotheosis; you never really got a full 'Demon Hunter' out of this even if there was an entire spec dedicated to it. It's more than just adding a few abilities, it's about presenting a new identity entirely.
Warriors aren't Blademasters even if they get Windwalking and Mirror Image talents, they're still gonna be Warriors with those abilities. Their entire rotations and kits are built for charging into battle, not relying on stealth and deception to gain an upper hand in battle.
This is why I say it would have to be on the level of a Prestige class addition, because the core Warrior gameplay has to be modified enough to accomodate bigger changes to the style of a Blademaster. They're not just Warriors with stealth and mirror image.
Heroes of the Storm exemplifies this the most. Play Garrosh or Varian, you feel like you're playing a Warrior. Play Samuro, and he's completely different. Windwalk and mirror image should be integrated into the gameplay, and not just as side additions that aren't exactly complimentary to the current Arms playstyle.