Having stated that, it was obvious that north and north east of landfall was going to experience record flooding. That was always a given, if it took the path that it took. Speeding up its forward motion, which was not predicted, actually lessened the severity of the flooding. IE - The storm had less time to apply its pressure and wind forces to water motion.
The increased forward speed was a two-edged sword. As a result, the storm made landfall at the Jersey Shore before the Monday evening high tide. But the wind around the back of the eye remnant ran right into NYC at high tide and helped pump the tide there to record levels.