There's no doubt that, if that's how it worked, the likelihood of integration and retention would be higher. That said, we need to recognize that we are in a bilingual province and that it's up to us to ensure the retention of newcomers.
For example, we give students from Africa extra English training to make sure they stay. Even if they want to preserve their French, which we all want, they could end up leaving the province and going elsewhere if they can't find work. So we have to strike some kind of balance to create conditions that will make it possible for them to continue living in French while giving them the tools, such as some mastery of English, to better integrate into the labour market.