That's obviously a challenge. We have to do a real balancing act so as not to fall into the situation you describe. French Canadian university institutions have made the choice to open their doors to all those from the majority who have the merit of wanting to learn in French. To my knowledge, no university has chosen to restrict itself to a target population. All those who want to learn and take the courses that are given are welcome at our institutions.
In some cases, the segment of anglophones who come from the immersion side is essential to the survival of those institutions. It's a challenge to ensure that French life is maintained, as francophones tend to be polite and switch to English. This requires efforts to create awareness. However, the doors of the institutions are open to enable them to meet that challenge. In any case, these places where there is a francophone majority, apart from Quebec's institutions, make it easier to learn the second language.