One important point here is that the second language requirement is an institutional one; it's not program specific. It's part of the institution's mission, so students who don't want that requirement can go elsewhere (as the student was told). I know of another university which requires all students to complete at least one course online. Should certain students be exempted from that requirement for one reason or another? (I'm pretty sure lots of blind students have completed online courses, for instance.)
Should disability accommodations trump institutional goals? If so, are all institutional distinctives really destined to vanish so that all that remains is what can be done anywhere by anyone?
This leads me towards thinking the requirement is non-essential, not the other way around. If it were mandated by the program, perhaps it would be mandated because of specific requirements for that field. When mandated by the university, it seems that it is more of a box to check.
I also think that students should be queried about WHAT they want to do with a given degree in cases like this. Perhaps the student could be told "You will not be able to be an effective researcher or college professor in Canadian politics with this degree" and the student will respond "That's ok, because I'm really doing a PhD because merely having one will enable me to get a job with a think tank that deals with politics in the western part of the country, etc." Perhaps he/she has no interest in the standard type of job the language requirement would prepare him/her for.
But that doesn't quite work , either, because unless they focus exclusively on western politics by ignoring all national laws that affect Western Canada, and we're arrived at at the national level by the conversations, altercations, and voting rules hammered out with French- as well as English-speaking politians, and at least some of the documentation is bound to be in French somewhere along the way.
But maybe I'm biased in this regard. Everyone needs to know more than one language, by my lights, and the refusal to put oneself out in all but the justifiable cases (like the one noted upthread where memory capacity issues/deficits preclude the kinds of learning needed for facility in actual language acquisition) smacks (to me) of thinly veiled jingoism, laziness, and philistinism.
And I thought that long before I ever started teaching French.
It also explains Trump, and his popularity among those who go in for the language of hate with little recourse to anything like a true language of love.