I think they plan on making some sweeping adjustments to tank damage as a whole in 3.2, so now that PLD has caught up enough gear-wise they didn't feel the need to make any big changes this patch. If they start focusing less on DPS and more on mitigation for tanks then things might naturally balance themselves out. It's kinda weird, and while I feel like PLD needs a DPS boost to some degree, SE has the hard data and the testing to make these kinds of decisions better than I can.