I went over and asked some Canadians. Apparently it's got to do specifically with securities. And the reason I couldn't find anything at .gc. is that securities are regulated by the provinces, not by a federal SEC-equivalent.
But this was a red herring anyway: the wording isn't "not outside of Canada", it's "not inside the US".
So it really depends on what your site's audience is. There's no point in going on and on about a new release if 90% of your audience isn't allowed to buy it.