Yes, those two observation decks are higher than anything planned for NYC, unless one is put very high up in One Vanderbilt. The Hines website offers this: "The building will be topped with a 60,000-square-foot observation deck that will occupy floors 57 and 58."
WTC 1 is at 1,250 feet, CN Tower is at 1,465 feet, and Sears is at 1,353 feet:
http://www.cntower.ca/en-ca/plan-your-visit/attractions/skypod.html
http://theskydeck.com/