At its very core, the Constitution protects aboriginal and treaty rights. The Supreme Court of Canada has interpreted that to mean, at a minimum, information, consultation, accommodation, and at times, consent. Canada now supports UNDRIP and the United Nations' position that UNDRIP applies at all international forums. It's great that Canada supported it, but it would have applied either way.
As for free, informed, and prior consent, we weren't even informed let alone consulted, so that's already violated the Constitution. The fact that there's no robust or specific protections for aboriginal and treaty rights that are constitutionally based at a minimum also violates the Constitution because the jurisdiction to make decisions over aboriginal and treaty rights is taken out of the hands of the state with these independent arbitration units and individuals. First nations don't even get to make submissions.
One of New Zealand's recommendations is that the Maori be included, that they do joint statements at arbitration or international tribunals, that the Maori be able to submit amicus briefs, for example, and that they're part of the New Zealand team that goes to any negotiations or any litigation. Canada hasn't even contemplated any of that.