I dont understand either, am sorry for the late response. Last time, I was gonna call for the graduate office for further info, then I saw you guys are in the same situation as mine. and you even recieved the email before my interview, thats crazy. Did you apply/consider to other schools as well ? I think I have to call them at the end of this week. Hopefully it doesnt come to that, but i really need the official offer to get my study permit done sooner. let me know if you receive the offer before the end of this week