Again the issue is not a pilot shortage, but a shortage of type rated / experienced pilots. The nature of Canadian aviation IMO is a fraction of what goes on in the US. Canada has a few, if but all 1 legacy carrier, lots of regionals, and a fraction of US population. Also, don't quote me, but i would think majority of our population travels to the US, not across Canada. Canadian aviation has always needed pilots, but at a very slow and steady rate.
This program, as you said creates a steady flow to fill the right seat, Canadian aviation is growing as well but at a steady rate, so these programs ensure some flow-through. Do your research, you'll find only the top students go on to FO right away from these programs, usually the testing is vigorous too, (i.e. PILAPTs after grad., academics, flight exam marks etc) Air Georgian, Provincial, and a few other regional airlines have partnered with a few schools offering iATPL as well, which gives you an interview, but again top students go on, not all.
Just to give you an idea, a few of my friends did the flight program at Seneca, only about 20% of the class according to them in 2013 went on to Jazz....the rest were left hanging and had to tough it out and find another way....
Maybe that'll increase in the coming years. Times are looking good, Westjet has steady expansion, and AC upgrading their regional fleet with the C-Series and 737 for the next decade, hopefully the government approves the desperately needed infrastructure funding for all Canadian airports to facilitate the growth.