I think that the mandatory language learning aspect can be used quite easily in an academic environment, at the primary and secondary levels, although results aren't always guaranteed either, simply because it's mandatory.
At university, study programs are often highly specialized, and require all kinds of knowledge in all kinds of fields, whether it be engineering, health sciences or law. Every discipline has its own approach to the field, but also perhaps to the role of language in that field. It's hard to consider imposing language knowledge when there really isn't any apparent or obvious reason for doing so.
The other approach would be to inform students that, if they earn an MBA and also speak French, that will open a lot more doors for them. I think that would encourage more students to learn it, and to learn it well too, because they'll have a goal in mind. It won't just be mandatory, but they'll say to themselves that, if they succeed, they may get a good job. I think that would be much more effective.