Someone should have done a bit more research before writing that. I don't recall any provincial organization or Wildlife Federation indicating that the drop in deer numbers is on account of CWD. And he's also completely wrong, there hasn't been a case of CWD in Manitoba. He states "It appears to be spreading to BC", then goes on to say "I hope we don't have to deal with this disease here."
In provinces that have had harsh winters in the past few years, it's no doubt that this is the major contributing factor to the decline, mainly areas of AB, SK and MB.
That said, predators and uncontrolled hunting certainly play a large part in areas, and since weather is the one thing that can't be controlled or governed, we need to revise how laws and legislation are written in order to attempt to control these contributors to the population decline.