As I've just said, the federal-provincial-territorial special advisory committee, which includes the chief medical officers of health, has been reviewing the evidence, much of which you have just cited.
The committee really wanted to ensure that there is flexibility according to local context and epidemiology. In provinces and territories where there hasn't been any community transmission, that's a bit different than in certain provinces where that has already occurred.
As we're exiting and beginning to cautiously and slowly relax some of the public measures, we have updated our recommendation on the use of non-medical masks. The way it is positioned right now—based on the evidence, but also on Canadian epidemiology—is that when the local epidemiology and rate of community transmission warrant it, the wearing of non-medical masks or cloth facial coverings is recommended for when you can't physically distance from others, particularly, as you can imagine, on public transport, in grocery stores and in retail places. It is a matter of your protecting others, so “I protect you and you protect me” is part of that.
As to what exactly happens in the individual jurisdictions like Toronto or Montreal, they need to have the flexibility to do that. It is, as you said, an added layer of protection, as long as everybody remembers that it doesn't necessarily negate the need for physical distancing and hygienic measures. It is certainly an added layer when you can't be assured that you can get that two-metre physical distance from others.