The difficulty here is that it has long been US policy to promote the exports of its intellectual property (such as its movies) and communications networks (such as the internet). Trade policy is almost always a two way street, particularly in the modern era in which arrangements like the "unequal treaties" that choked the Qing dynasty are highly unusual. So banning Tiktok necessarily results in reciprocal bans. Canada does not have similar concerns as the US does because it is our little gas station whose pretensions to independence we humor and they do not export IP or communications technologies at the same scale as we do.