The evidence isn't really clear that changing it alone won't do anything. The biggest factor to go with it, I think, is that you have a country that already believes in women's equality. I think if you had a country that didn't believe in women's equality and where women weren't, as I mentioned, extremely well educated, in the workforce, all of those things, then I don't think, on its own, it would make a difference.
On the evidence, it seems that Canada is positioned to have women benefit from a move to proportional representation. We can only cite the evidence as far as it goes.