Adding new AI and a new skin makes them new. A whole new patrol area filled with loot. Missions on Phobos, Mercury, and the Dreadnaught. More missions and strikes than both the smaller dlcs combined. 3+ crucible gamemodes. More than 4 multiplayer maps(I don't have a number for those.). Redesigned and rethought weapon designs that aren't reskins of old weapons and actually have something tondo with their producers. Their "Biggest Raid Yet". Strikes that are redesigned and rethought so that the bosses aren't just bullet sponges.