I had to leave my job due to moving and was in the same situation. They probably already sent out your w-2 to whatever the previous address was that they had on file for you. I would suggest calling and simply explain that you need to get a copy of it. (Not sure about all workplaces but mine forwarded me a link to a website with my login information) No waiting for it to come in the mail or anything. It was super easy. Hope this helps.
