The controversy over Sun News has been frequently misrepresented. The owners of the channel had previously used their license for a general entertainment network that was entitled to mandatory carriage on Canadian cable systems. When they proposed switching to a news genre (with a conservative slant), the opposition was not to their doing so, it was to their continuing to have a license that gave them mandatory carriage. They ultimately abandoned efforts to get such a mandatory carriage license and launched as an optional carriage service. By way of comparison, broadcast television stations in the US have mandatory carriage rights, but a non broadcast service such as Fox News (or CNN or ESPN etc) do not. So, in essence, Sun News has the same status in Canada as Fox News -- it certainly wasn't "kept out of" the country.

While Canadian law provides on its face for greater regulation of content than US law, and while Sun News has managed to engage in conduct that drew regulatory scrutiny on quite a few occasions already, in a great many of those instances, the regulators concluded that, despite widespread complaints, Sun News did not violate any rules. And in the rare instance where it has been found to have violated the rules, the punishment has been little more than a slap on the wrist: having to broadcast a statement that it was found to have violated a rule. Whoop. De. Doo.

The bottom line is that apart from the fact that any attempt in the US to impose Canadian style regulation on the content delivered by a non-broadcast network almost certainly would be struck down under existing Supreme Court precedent, the Canadian law hasn't stopped Sun News from doing pretty much whatever it wants.