The federal government does though - or at least it used to, I don't know about now - when I was an undergrad there were projections readily available that showed anticipated demand for each type of degree for the next 10 years. I cannot remember which part of the government did that - StatsCan or Industry Canada would be my guess.
One can also just scan the job boards and see what fields are in demand and which aren't. How about this - before you can get a student loan you have to show you know the anticipated demand for your field four years from "now"? Even if they are just parroting what someone else told them was the right answer at least they can then never claim ignorance.