Thanks for that interesting information. One can see the wisdom of such a constitutional provision when the country was a young democracy. Should a territory in the 'Wild West' do something outrageous, the federal government could restore normalcy. As you'd expect, as Canada matured as a nation the provision was used less and less frequently. 

Imagining a circumstance today which might invoke that constitutional veto isn't easy. It would have to be something extreme, something that necessitated an immediate federal intervention lest grave human rights abuses were committed by a province. Quebec's anti-veil law is stupid,  bigoted, and an ugly stain on our country. But it's also petty. It doesn't rise to the level of a serious human rights violation. There are other ways to deal with it, and I have no doubt those ways will be put to good use.