Specifically, we removed Dragonpowder, Star Metal Picks and Skeleton Keys so people weren’t farming them like crazy. One player reported getting 20-30 Star Metal Picks and 15 Skeleton Keys in about half an hour, so for balancing sake we needed to take them out.
You will still get things like Legendary Repair Kits and Black and White Dyes, as Rorik pointed out, and practically every other crafting material in the game. 