Here's why we don't have them:
You've likely seen WoD models in 3.3.5, the reason for this is there is a variety of backporting tools avaliable to 3.3.5, but that's where these types of tools sadly ended. the issue was mostly to do with the m2 format, because we have no base file that's not an M2, and our M2 is different from later versions.
We essentially have to find a way to work on, convert and then implement the new model. And when I mean 'work on' I mean, seriously, we're talking about TONS of work, fixing up a whole model, even simplifying it's animations and textures.
The main issue is there 'WAS' a huge issue between porting TLK+ models in the past because there were no tools available.
Today, it is possible to use those models, but to also use the animations and make sure the model doesn't instantly break is a ton of work.
Personally, I've always thought it's possible to do it, since MoP and cata models can now 'kinda' be taken over (albeit with a ton of extra work) it should be more than possible for us to do so on 1.12.1.
