Analysis of information sources in references of the Wikipedia article "Toronto and York Radial Railway" in English language version.
Yes, all the Toronto lines ran at 500 to 600V DC with one exception. The Toronto Suburban line to Guelph ran on 1500V DC from Keele and St Clair until it hit the streets of Gur...streets of Guelph on its way to the GT/CN station. For that short distance, it ran on the city system voltage of 500 to 600 Volts. It was not considered good practice to have 1500V over city streets in case the overhead came down but there were some exceptions.
Chapter 5 - The Toronto & York Radial Railway
Chapter 7 - Tommy Church vs. William Mackenzie
Chapter 8 - Hydro Radials, Clean-Up Deals, and Waterfront Grabs
Chapter 9 - Who Wants to Run the Radials?
Chapter 2 - The Mighty Metropolitan Moves North