I should have said in my original post that it's *very likely* that it will be deferred (not definitive at this point), but regardless, the whole thing seems very strange and like you said, the exact same thing happened with the Ridout bridge recently.
I'm just wondering what the approvals would be for. As far as I'm aware, the city already owns the land they need for the widening. Sunningdale does go over the Medway Creek, and a new bridge crossing is required, so maybe it could be environmental related approvals (like with the Ridout bridge).
Is it possible that there was some new legislation (at the federal or provincial level) passed very recently? As the Sunningdale EA was completed in 2012, you'd think all of the necessary approvals would have taken place within the last decade.