The government's position is fairly well-known. The support that was acknowledged for the UN Declaration for the Rights of Indigenous Peoples was carefully worded to recall the concerns that Canada put on the record in 2007 at the United Nations about several of the terms in the declaration, including the one you're mentioning on free, prior, and informed consent.
The wording of the UN declaration comes pretty close to articulating a veto power for indigenous peoples in development projects. That is not at all where the law of Canada is. From 2007 forward, the government has repeatedly articulated that the conduct of public affairs in this country is under the law of this country, our Constitution, section 35, including the duty to consult. The UN declaration is not a legally binding document, so the “free, prior, and informed consent” provision that you refer to is of interest, but in practical terms, how section 35 is implemented in this country is much more significant.