I'd just like to add that I'm not certain of the reference you have for 2005 and the changes that were made then. I'm not aware of any environmental testing that was required by CFIA prior to this most recent policy. However, there was a requirement to take product samples to be tested for listeria monocytogenes as part of export requirements, as part of the FSIS USDA government regulations. So there were product samples required for facilities that would be exporting to the U.S.
Just to be clear, testing of product for LM is quite different from testing the environment for the organism.