We've had The Walking Dead trailer in Fallout 4 (opens in new tab), Battlefield 1 in GTA 5 (opens in new tab), and now the Warcraft movie in, well, World of Warcraft. I will admit that makes some sense.
More accurately, you're watching the Warcraft trailer (opens in new tab) recreated using World of Warcraft assets, skilfully animated and edited by Ivan Kuzkin (opens in new tab). With a little help in post-production, it looks just as slick as the movie—better whenever a painfully prop-like shield is on-screen. I'd watch this Warcraft, or play a gritty World of Warcraft reboot along these lines.
For the sceptics, Kuzkin has provided a side-by-side comparison: