The Supreme Court of Canada, in the case of the Société des Acadiens et Acadiennes du Nouveau-Brunswick, had decided that a party could use the language of its choice, but that the judge was not obliged to hear it in that language. This decision has never been overturned. The interpretation principles underlying this decision were overturned in the Beaulac affair, but the issue of bilingualism for justices never came back before a court since then, and this was for a very simple reason: the Official Languages Act at the federal level and the Official Languages Act in New Brunswick were amended to recognize the right to be heard directly by a judge who understands without help from interpretation.
According to the new principles governing interpretation, if this issue was raised again before the Supreme Court, I would be ready to bet my shirt and my tie that the Supreme Court would overturn the decision made in the case of the Société des Acadiens et Acadiennes du Nouveau-Brunswick.