Not only that;
In legal aspects, Warmane can be sued and shut down immediatly for using current content as available content in a private server. Reviving old content is not totally ilegal but using the content that is being used in the current legal version of the game with the objective of offering the same experience is actually suable.
Plus, at other members already stated, they have their hands full of work with the current contents available (WOTLK, Cata & MoP). So I really doubt they want to carry the burden of developing WoD anytime soon.
As other member also refered, it would be easier for you to buy Legion and play on Retail. Since you can actually play for free (I've got my subscription paid with gold until August 2016) just take the time to grind a little bit of gold and enjoy your free to play game time. Taking over the auction house, farm, etc. You got several ways of making a lot of incomes in there.
With that said, don't expect Legion in this community anytime soon.