No. Because you are adding a Demon Themed spec to a class which already incorporates the Demon theme and you'd be adding gameplay, not removing it. Growing the class, not changing it. And the DH would be a separate from Warlocks as an Aff Warlock is separate from a Demo Warlock......linked via the gameplay mechanic of the same base class, butt still two different aspects of the same baseline class.
Blizzard keeps telling us that the way the game is set up, there are 34 classes in game that they need to be concerned with. 34...which means has its own design space with its own lore, abilities, history, gameplay, all set within the larger design space of the 11 baseline classes. Perhaps you'd be better visualising the issue that way - that the DH would effectively be a separate class encompassed within the baseline Warlock spec because of its shared theme, concepts, abilities, etc.
The class system after all is only a gameplay abstract. Each spec is different and a specialist such as an Aff Warlock does not become a Demo Warlock overnight.
You? You are fine with changing the design space. You don't like this part of the DH? That part won't fit? Drop it. That's doable...but you can't simply chop and change the design space and expect to have no impact on the end result. If you change the design space, there will be an impact.
I'm fine with expanding the class. I'm totally OK with adding the DH to the Warlock; that adds gameplay and flexibility to the Warlock. That doesn't compromise either the classwide lore of the Warlock or the spec specific lore of the DH. From a game design point of view, it takes full advantage of the design space overlap - its made a liability into an asset. From a marketing point of view, it buffs one of the least popular classes and gets Demon Hunters into the game. From a developers point of view, it allows Blizzard to gain additional value form all those tanking and test models they tried.You are absolutely fine with that. It's a hypocrisy that defeats your entire argument.
What I'm not fine with, what Blizzard doesn't appear to be fine with, is chopping and changing the design space so the end result, the Demon Hunter, is not what we see in game. You've been prepared to drop the lore we have for the class. To drop the name. To give away the abilities. To change the class concepts. You know there is an overlap, but your solution is to simply put another class in the same role. You've lost sight of the actual goal of the exercise...to add a Demon Hunter to the game.
You are 100% correct that Blizzard could add a class with a totally different design space to the game. No argument there. Where you are wrong is in suggesting this would be a Demon Hunter.
A Demon Hunter who doesn't absorb Demons for power? Who doesn't make pacts so he can use Demon Magics? Who can't turn into a Demon? Who doesn't look like a Demon Hunter? Who has no lore linkage to Demons or Illidan? Who can't even be called a Demon Hunter?
Call it what you will...but that isn't a Demon Hunter.
Confusing adding to the Warlocks as a retcon of some sort - and nothing need change for any of the existing specs that requires a retcon - is a result of YOUR view of the class. Noone suggests Mages couldn't have a melee spec, probably because we already have examples of BattleMages and the Highborne Enchanted Magi. Indeed, the lore we have suggests that Mages took to heart the lessons Conjurers learned in the First War and emphasised physical training as well as their more usual scholarly pursuits so they could better handle the stresses of combat -and many Alliance Warlocks used to be Mages. Plus, we already have player based caster-melee hybrids so the only "retcon" that is needed is your viewpoint that a class can't have an additional role added when it contradicts how you see the class.
However, regardless of how you feel about the class, or the various aspects and importance of the overlap, the simple fact remains that Blizzard feels there is a design overlap. Given that, we need to ask if Blizzard is willing to either live with the resulting duplication and its associated costs, or if it is willing to change the design so there is no overlap. The answer to both appears to be no...for valid game design purposes...and as such, the question is how to add the DH to the game using the design space it has.
If we need to use the existing design space, and aren't willing to live with duplication, then adding it as a Warlock 4th spec is the most viable option left. There's no question that a DH could be better explored as a separate class. But Blizzard gains nothing from doing so. Nor does the game. Indeed, given that the design space overlap exists, a separate class would be detrimental in many ways - impacting negatively upon existing classes and requiring Blizzard to duplicate work and costing it the opportunity to add a new class.
Why would no NElf ever be a Demon summoning Warlock? Why would this require a retcon? Can we not have some NElfs going rogue just as DHs appears to do? Another Athrikus or Tyranis? The Higborne? There have been NElfs Warlocks and Demon Summoners before. There's little reason we can't see such in game.No Night Elf would be a Demo-summoning Warlock. You are willing to retcon this to allow Demon Hunters to be a part of Warlocks. Do you not see the entire fallacy behind this?
EJL