Azeroth was created by some doods that fly around outer space. Orcs came through a portal. This isn't just medieval, never has been.
Buuuuut, Northrend and the Lich King expansion is definitely less outer space and more down to Azeroth like you probably expected the game to be when you bought it.
Orcs & Humans, maybe, but I'm going to bet there aren't too many people that jumped straight from the first Warcraft to Burning Crusade and were shocked and appalled by the direction the story has gone. If you've played Warcraft II and after then you know it's not just about Azeroth, it's not just knights fighting cave trolls and dragons.