The twist is (as the article mentions - seemingly the first time anyone has bothered to bring it up), for those of us who live in the 416, but not in the downtown core.
We pay our property taxes to the City of Toronto, which presumably includes upkeep for the DVP/Gardiner, and TTC funding.
Tolling us would represent a double-taxation, and to date, I've neither read nor heard anything about how Torontonians who use the DVP would receive rebates or exemptions from tolling.

In any case, this should be a lesson to voters: Beware of Liberals (or any politicians) bearing promises of gifts.
I'll stick to the party that makes the fewest grandiose promises, but also seeks to minimize its reach into my life (and my bank account).