I think that's for general undergraduate admissions. The supplementary application was due in February, so they wouldn't be able to send out any offers until all of the applications have been...
I was surprised as well, but when I went to sign up for my CASPer test they had one date in April available. When I checked last year's thread it seemed like they also had some offers go out in March,...
I still haven't heard anything from Western yet. I'm wondering when they will start sending acceptances since some of the Casper test dates go up until