Ugh, what?!? Do you even have an Apple TV4?
Siri has been available in Canada on the 4th Gen Apple TV since day one.
Really !? Maybe because I set it in French...
Still, Siri in French has existed since at least the last 5 years, I can't explain why it's not enabled on my Apple TV.
Edit : Confirmed on Apple's page. Siri on Apple TV is available in France, but not in Quebec yet............