I’m going to take a contrarian view here.
I was fully prepared to take the view “ the consultation request  is unreasonable” going into the article
Then i reread the facts as presented ( its all i have to go on)
And if those facts are correct I would submit that the band is well within its rights to demand to be consulted .
Either we have property rights or we don’t.
If you want unfettered access to a piece of land Mr Government. Go all in ; “pay up “ ; expropriate.
If a deal has a term limit it means it has a shelf life ( ask Newfoundland) unless stipulated ;  aren’t the terms subject for review at the end of the deal, like a lease?
I am not intimate with details,but with the facts given;  they dont leave me thinking the province has dealt with the cleanest of hands. 
Finally; if this was a 50 year deal affecting the water lines of Lake Muskoka and Lake Joseph I think this would be a very different conversation between parties.