This image seems to indicate that the expansion will launch on September 20, 2016, and will only be making its way to PS4 and Xbox One, meaning not to PS3 and Xbox 360. In addition, Xbox.com had a listing posted that has also since been removed. The expansion had the following description:
Destiny: Rise of Iron is the next highly anticipated expansion to the Destiny universe. The wall which stood for centuries along the southern border of Old Russia has collapsed. Fallen mutants now scavenge the tombs of the Golden Age, and the plague they have unearthed is more dangerous than even they understand. Join Lord Saladin. Journey into the Plaguelands. Learn the fate of the Iron Lords and stop the growing threat before it is too late.
New Story Campaign & Quests
New Armour and Gear
Maximum Light Increase
New Plaguelands Zone & Social Space
New Crucible Mode & Maps
New Enemy Faction and Bosses
Stay tuned to The Outerhaven for more E3 2016 news and for the future of Destiny.