Metro Centre took Project Toronto off the radar, since it was less radical and actually proposed by a developer. It was the massive redevelopment scheme that would have replaced Union Station with octagonal office towers and built a new station south. It would have been interesting if Eaton worked with Buckminster Fuller and created the Eaton Centre as a glass pyramid with other elements from Project Toronto.
This I know from Unbuilt Toronto, which is a great read. At times it's almost painful to see the beautiful proposals which never made, particularly in the time of the City Beautiful movement. Other times, it's quite a relief to see what didn't make it.