I agree with most of your statement, but I believe this is mis-attributed to Metzen. I have gone back and searched and I can find him saying it was the last thing he worked on, but no where can I find him saying that he was surprised the Alliance didn’t attack first, the horde did, or any of that. He did say he was surprised how it all turned out, because it’s not what they originally planned for Sylvanas, but I think people took that and extrapolated to far and put words into his mouth.