I'm not sure! I would assume they do, but that's the case with lots of schools, scheduling is tough. I know they've also done skype interviews, but I have no idea how that affects your chances, because the day is so crucial in getting to know you. I was told there were lots of great applicants this year, so maybe that's why it's last minute...perhaps profs are having a tough time choosing!
My guess is you won't hear from Guelph until later this evening...faculty have the day to get their choices in, so don't freak out if you don't hear anything until tonight!