Wasn't this a way for the natives to be guaranteed land of their own and the ability to maintain their heritage and distinctive society instead of being swallowed up the large masses of the rest of the population? Similar to how the Quebecois are very concerned about maintaining their heritage.
I don't know the history of the negotiations but I would not be surprised if these were some of the things the natives requested.
In old days the law seems preoccupied with westernizing Indians
Things like the Enfranchisement Act could make them official British subjects by relinquishing their Indian rights
Many of them took advantage, others protested
Current law essentially supersedes all provincial legislation and makes any interactions with them at a federal level
In 1985 most of the loss of Indian status issues (eg being a bastard, marrying outside tribe, voting in elections etc) were stripped away and recently government introduced legislation to recognize more status Indians (wrongly in my op)