He did write zone stories before becoming creative director. As I mentioned before, he wrote the horde Stonetalon story and wasn’t informed that the other writers wanted to move Garrosh into an antagonistic role instead of a heroic one. It is why Stonetalon feels odd when it comes to Garroshs’ characterization throughout TBC, Wrath, Cata and MoP. Where the overall narrative has him go on a negative character arc and then there is one story where he goes on a positive one.
He was a junior then lead quest designer before becoming creative director.