The title is deceiving because the author of the article can only speculate on why, and his quote is from an analyst.
Anyway: This could all be just timing.
The international Kindle seems to be based on 3G/GSM of some sort. Up until this week, the only GSM provider in Canada has been Rogers. Just this week we've received news that both Telus and Bell will be offering the iPhone in Canada, on their shiny new GSM-compatible joint-built network.
Is it possible Amazon reached a deal with a 3G provider in Canada -- just not Rogers?