First of all, Sirius is available in Canada. Second, they decided to NOT include Sirius Canada as an Alexa skill (which is a big reason I purchased it, so I hope this changes).
One other big gripe I have is why they felt the need to muck things up by differentiating between US english and Canadian english. There's a bigger difference between American accents then there is between US and Canadian accents! If Alexa can understand someone from Boston or Alabama, it'll understand someone from Canada!