In his address to the General Assembly before the vote, Canada's UN ambassador, John McNee, said Canada had "significant concerns" over the declaration's wording on provisions addressing lands and resources, as well as another article calling on states to obtain prior informed consent with indigenous groups before enacting new laws or administrative measures.
Article 26 of the UN declaration states: "Indigenous peoples have the right to the lands, territories and resources which they have traditionally owned, occupied or otherwise used or acquired."
From CBC news Canada here
Indigenous people, already marginalised, ignored, living more and more restricted lives, subjected to discrimination because of who they are and where they are - and also in the way of the progress of the capitalist craving for more profit at whatever cost. Their ancestors having been there for generations before the colonialists discovered their land seems to be no more than an inconvenience to the current captains of capitalism keen to exploit the fossil fuels and complete their pipelines. Capitalism cares for profit, not people.