I no longer live in a big Canadian city, so I had to special-order my Canadian version of Heart Station. Apparently, there are some places in Canada that you can walk in and pick up her Singles Collection (Vol 1), Ultra Blue and Heart Station. I own the latter - and I went through a hell of a lot of trouble getting my free promo poster for my HS album. I have yet to find a poster frame protector that would fit this Hikki poster, it being B2 format.
I'm confident that if they did sell Hikki's music in the US, it would do much better in Canada. Although Canada does have a very large Chinese population (which I'm sure helps sales), I think that the USA has a larger Hikki fanbase at the moment (and possibly more Chinese-Americans, too).
Perhaps the only way to understand why EMI Music Canada has decided to carry Hikaru stuff is to email them yourself. Is anyone willing?