Pretty sure this is entirely intended to be a PVP specific change but was also added to PVE as they couldn't come up with a way around it and it didn't dramatically shift anything DRK-related in PVE anyway. 3s is good, it means your next DA will be up sooner in the GCD. I always found it a bit frustrating that DA would always come up at the tail end of my GCD and this sort of alleviates that slightly (though it can still happen). DRK also doesn't really need a DPS buff in PVE... it's more than capable of pulling high numbers. Reprisal, DA + DM, and Delirium (with no MNK, and in some cases even with MNK) are very valuable things to bring to the raid if utilized correctly. I think, moving forward, we could see some issues arise with DRK depending on how the raids are made but for now there's really no need for adjustments. Obviously the DRK + PLD thing needs looking into as a viable tanking composition, but that's for another patch (though hopefully sooner rather than later).