Doing some searching online it seems the claim normally made is that all steel rivets wouldn't have prevented the sinking but could have slowed it enough to allow more passengers to be rescued.
To provide a bit more context lower grade iron rivets were used because of supply shortages at the time. Higher quality steel rivets were still used for the midsection of the boat with iron rivets being used on the ends.
Is the current makeup of city council one that can work well with Chow? I don't follow local Toronto politics to closely.