Pearl Milling is a Product of Canada. The others are Product of USA. I've been using Pearl since the first wave of tariffs (it's just as good). I have returned to turning Product of USA products upside down.
Not necessarily. These labels refer to the manufacturing of the product only, it does not stipulate who owns the parent company that made it.
It means that 98% or more of the money that was spent making the thing (ingredients and labor) was spent in Canada.
This is still a good thing. Buying things that are "Made in Canada"(good), "Product of Canada" (better), or "100% Canadian" (best) ensures that the majority of the money comes into or stays in Canada (unless you're working with something with profit margins over 100% which is quite rare). Anything that doesnt have one of these labels right now means that the majority of the money spent making it was spent somewhere else and the product shipped here.