I think that what you are saying is largely unnecessary. I've touched on this before, but I'm consistently amazed at how future proof they made the game. When they were first creating WoW, they made a lot of incredibly smart decisions that allowed them to continue with what is essentially a ten year old engine at this point.
A good example is projectile effects. Back in Vanilla, a spell like a Hunter's
Glaive Toss wouldn't be possible to code. If you threw a fireball at someone, it wouldn't do damage to all targets it passed through. The server recognized that your character cast it, would calculate if it hit or not based on a %chance determined by hit rating, then would deal damage to the target. What was in the way was irrelevant as long as your character had line of sight.
But because the original engine was, I believe, designed to be easy to modify and add on to when the time came, they were able to add hit detection in. Now you can have spells like Glaive Toss too. If you asked me if that kind of thing was possible back in Vanilla, I would have said no. But time and time again they have surprised me with just how well they can push the engine.
I really do think that Blizzard has some incredibly brilliant engineers on their team. Some of the **** they pull, from a programmer's perspective, seems like absolute witchcraft to me. I still think there's some kind of faustian deal involved.
I don't think a remake is due yet. WoW might be running on an ancient engine at this point, but they have so many brilliant people working for them they have already been able to do way more than I thought they would, and I don't really see that changing any time soon.