The requirements have changed. There are a number of factors.
I do not want to get into the technical details, but one example is the way a building can be audited. The United States and the European Union can accept a non-governmental audit, but Canada cannot. Those audits are often conducted by multinational companies. So the product will be approved by the United States and the European Union, but not by Canada. It is not worth it for the company to invest in a government audit for the Canadian market alone.