I am not sure how the wording is not used. It was the department's perspective that the wording is quite reflective in clause 2: "nothing in the law shall be construed so as to abrogate or derogate from the protection provided for existing aboriginal treaty rights of the aboriginal peoples of Canada by the recognition and affirmation of those rights in section 35 of the Constitution Act, 1982."
I am not sure how the land claims agreement provisions would be interpreted differently.