To clarify for anyone not interested in reading the full article, it is exactly as
@mdrejhon reported recently - you can now link your Presto card to your account and tap your card to expedite the bike unlocking process. You are not actually paying with the Presto card, it is just being used to identify you--you still need an account with a payment method linked as before. Still handy, but I'd like to see SoBi--and BikeShare Toronto for that matter--support having any Presto card holder without an account just walk up and tap their card to rent a bike, though the logistics (namely a security deposit for the bike) are difficult.