Only I don't think history suggests they were ever THAT vibrant to be honest. They always played a back-seat role to Queen & King.
On the plus side, I think an argument against one-way streets can be made in a city that is going through tough times (i.e., Hamilton for the last 30 years) as it can harm street life somewhat and make sidewalks unpleasant. However, in a city as big and successful as Toronto, it's probably not too much of a concern as the sidewalks will be animated regardless. Basically, we are closer to the NYC example than the Hamilton.
Admittedly, there may be some room for street rationalization through our core (north-south too!) that could free-up extra sidewalk space for bike lanes, wider sidewalks, too. However, unless transit continues to run bi-directional on these streets, it will be a non-starter for most. And I think we need a DRL prior to doing any of this as well.