I would assume that we will hear back not before May (if ranked high enough on the alternate list), since funds won't be available unless people start rejecting the offer (and usually they have around a month to do so).
The process this year seems very disorganized.
Based on the auto-reply that we have received via email, our rankings should be emailed in mid April. So, I believe that it's another letter.
In addition to the auto reply, I got an actual reply stating the same thing:
Hello,
The letters with the results of the 2019 PGSD competition were mailed last Friday.
Thanks,
Scholarships and Fellowships Division
It should be out anytime between now and the 31st of March. In 2017, the results came out around the 15th, and last year it was on the 28th. So we can't really predict. Hoping it will be out this week.