The critical question is whether francophone litigants who come to the court will be understood by someone. Of course, they should have access to translation and interpretation service. I agree with you, those services are excellent. However, with simultaneous interpretation, it is more difficult to understand the argument being made. In my view, that puts litigants at a disadvantage, especially at the Supreme Court of Canada.
On May 30th, 2017. See this statement in context.