I believe that the Toronto model follows the territoriality principle. Territoriality is not only a matter of law, as in Belgium or Switzerland. Territoriality is also all about numbers.
An immigrant who settles in Toronto will speak English because there's no other choice. Immigrants who settle in Rome will speak Italian, no matter what their native language might be. There is no legislation on it. These countries do not need it, because the principle of territoriality is based on numbers.
Quebec could increase the number of transfers to French with additional linguistic territorialization, but it would be impossible to take this very far and caution is advisable.
Estimates show a maximum of 7,000, 8,000 or 10,000 language transfers per year in Quebec, in all directions. This includes not only immigrants who change their language from French to English, but also from English to French. This represents a net annual increase of 2,000 francophones.
With the introduction of new measures, this could increase from 2,000 to 4,000, and 2,000 is a highly convergent estimate. The number could easily be doubled, but it would be very small compared to the 20,000 or 25,000 missing francophone births.