The government isn't accepting bitcoin as a means of settling tax payments.
I think that the main takeaway from the article is that, a third party middleman is used in order to convert the BTC into CAD first, before the government collects the tax payments. It's not as if the government has the payment infrastructure set up in bitcoin and ready to go, at least not at this stage.
In this case, there is zero exchange rate risks for the government receiving the payment, and it's almost the same from their perspective compared to traditional means of payment through fiat. It's most likely just hyped up news that in reality, won't really make any difference.