It's a place holder. Even Canadian corporations would likely file in the U.S. first, because for Canadian corporations the biggest market in the world is the U.S. So there would be a filing in the U.S. for a variety of technical reasons. If the filing starts there, there are certain aspects of U.S. patent law, for instance, that favour filings that are in the U.S. first. It's a major market.
This doesn't preclude our filing in Canada at the appropriate time—or anywhere in the world, for that matter.