Not sure about historically, but the current riding doesn't include most of the area, or people, who would have been in East York.
A good chunk of the people who used to live in East York, are paradoxically now in the North York council area, rather than the Toronto-East York council area! A lot of people don't even know where East York was ... I see people calling the Gerrard Corridor "East York", and others who have no idea that Laird, Thorncliffe, and Leaside were all in East York!
It's dead, Jim.