If Rona is selling them it must be old stock or a regional purchasing thing.
I was in the two large Rona Stores in Winnipeg since you posted this and neither of them had any of the cheaters for sale.
Also did not see them in the other major big box chain stores in Winnipeg either.
First time I remember seeing one is in the 60's when my dad bought one so he could use his new electric drill. Our house was built in the 50s and did not have grounded wiring.
When I was in Ontario I saw a lot of those at dollar stores, pointed out to the store owners that they were illegal in Canada, and got the shrug 'we just sell them, we know nothing of this electrical code of which you speak' .
As gfretwell mentioned, unless there's a bodycount, nobody is going to enforce sadly.
I don't even see what grounds Canadian customs could use to sieze these things. They may be non code conforming but that doesn't make them "illegal". The current code is dead front plug caps but I still see dusty old plugs with screws and a fiber washer on the shelf. They also still sell edison base fuses (not S type)