The Class Item from Sundered Doctrine does not appear to drop from either normal or master mode. Focusing it via the vault chest after the boss using the focusing system unlocked after the quest yields a regular 2.0 class item (or artifice armor version, on master mode) without the new set bonus. As far as I, the multiple people I've done completions with, and the several communities I've investigated with have been able to determine, there may currently be no source for the armor 3.0 version of the item. This is problematic, as it means the 4 piece set bonus can't be utilized without using an exotic class item on the prismatic glass. Leaving pure Strand unable to use a strand centric class bonus.