The wowsource article only states that "Archilon Wrynn" was rumored to be played by Mark Hildebrandt, in fact he was also rumored to play Varian, which turned out to be false, both debunked by the actor himself, which was mentioned on a BlizzPlanet article about that, though it was edited out apparently. Luckily, Google still has that paragraph cached:
I contacted actor Mark Hildebrandt, and he debunked the rumor on IMDB that he is involved in the Warcraft Movie. “If there was any interaction between my Agent and Legendary Pictures it would have already happened. That is not the first time I have been associated with the Warcraft film, but I am not aware of any involvement.”—said Mark Hildebrandt.