The highway interchange is a purely provincial government decision. There is nothing Saanich could say about it because the province already has all the land. There is no need to consult with anyone.
This intersection is likely on some list of to-do's and is getting closer to reality as projects are completed. HWY1/Mackenzie must be the single largest bottleneck on the south Island and needs to be addressed purely for the sake of connecting the western communities/south Island with the Saanich Peninsula, YYJ and the Swartz Bay.
I imagine one of the reasons why nothing has happened here is the sheer cost of building the interchange. Obviously a traditional intersection with traffic lights won't fly considering the volume of traffic turning east off of the 1 so we'd be looking at a combination of flyovers and traffic circles to keep the heavy volume of traffic flowing. I can't imagine that this would cost anywhere south of $40-million.