I believe American booze is coming off the shelves in most - if not all - provinces, including my own (Nova Scotia). All provinces have liquor boards/commissions, which are crown corporations. They are a legacy of prohibition which, after repeal, were stood up to control all wholesale and most retail alcohol sales. Provincial governments are loath to give up their monopolies, as they are cash cows.
I've never been a fan of this arrangement, as there is no real competition and you'll find the exact same products on every provincial liquor store shelf, which limits selection.
But, in this situation, I appreciate their ability to send a strong message. If you want to play hardball with us, we'll do the same.