What they want and what they eventually have to compromise to are two different things.
I, as a starter to discussions, could want that they not be involved at all. So between me and them nothing would get done, Ever.
I see that their communities in the neighbouthood need the jobs and services while they have to come to the conclusion that Mines ( not just one ) will be built and that their order of construction ( per Tin Man) will be done on basic of economics reasons and not on wishes. They need the east-west road as much as the miners and along with that road is Noront's mine. There is no way around that particularly when that road will ease railway construction ( that is north-south version ).

"They feel that mining the chromite first would benefit their communities and initiatives."
So Noront's nickel mine is of no benefit to them? Hallo?
Mine is only in the planning stage and they already have seen some small benefits.

For rehabilitation of the region afterwards, that is what environmental assesments are for. It is a now common standard that after mining, as is after clear cutting forests, that the terrain is to be restored.

Seems to me they are not seeing the whole picture but only in self interested pieces.

Mark2: Take a look into Treaty 9 ( I only did superficially) and you will not likely see anything in there about them having anything to say about underground assets. Quite to the contrary, governments have first priority over above ground assets.
The natives ceeded many so called 'rights' that they may have had in exchange for federal support, i.e. payments ( call it welfare by more commonly understood terms used today).