The ban only applies to stations that are members of the Canadian Broadcast Standards Commission, which is not a government agency. In fact, the CBC, a coast to coast government owned radio station played the song at least two times while reporting the Canadian Broadcast Standards Commission's ban. Canadians can still listen to the song, just not on radio stations that belong to the CBSC.
Just as anyone can still read and buy new copies of the Adventures Of Huckleberry Finn, just not in the edition that has been abridged.