Product monographs are data driven. They are drafted by pharmaceutical companies like Purdue and others. They are reviewed and scrutinized internally before they are sent to the regulator and of course at the regulator, Health Canada included. It is a mutual agreement that the product is adequately and appropriately represented by all of the language in a product monograph.
Product monographs, when they are produced, are supposed to represent the state of knowledge and the current understanding of both the product and the discipline that exists at that time. That was, to my knowledge, the case with both OxyNEO, when it was introduced in 2012 here in Canada, and with OxyContin, when it was introduced in 1996 here in the same way.