Just a slight correction, Humber Bay will become the densest neighborhood in Canada once the Mondelez lands are developed. Even denser than St.James Town. At the moment I believe it's #2 in Canada.Parklawn and lakeshore will become one of the most densily populated areas in GTA, outside of the core of Toronto. Its logical progression for the OL to extend itself out to Parklawn. Humber Bay is is already plagued with poor transit as is, with excess of over 40 towers already and another 18 in the plans....this area needs it. Very short sighted by the province to not consider it.
We're not going to see the Ontario Line extended westwards for decades so dont put to much of your breath into deciding where it should go.