I'm no linguist, and my Innu is very limited, but Nitassinan refers to the territory, our land, the land. It's a powerful term, obviously, given the relationship that first nations, Inuit and Métis people have with the land. For them, it's meaningful.
Beyond that, the land means the entire territory, which is immense, and it's not just one place. Certain places can be important, but the name “Nitassinan” covers all of it, just as the name “Côte-Nord” covers all of it. I think that's important.
Speaking personally, I think that putting the two territories on an equal footing and connecting them is a wonderful idea. Naturally, they agree and they're behind the proposal.