Rare spawns seem to be broken in WW as of the patch. The day before they were spawning at the 200% rate promised for the even, but since patch they don't seem to be spawning at all, or at normal rate and I'm unlucky. I also noticed that some spawn points for the Dwarves in WW (the PHes for a rare) don't seem to be active. I know this from pulling to a spot I like to pull to usually has a dwarf spawn near it as I play...haven't seen a dwarf spawn in that spot since the emergency shutdown last night. Many in the zone today shared the same opinion on this. Please take a look.
I got Backstone to spawn just 15min ago, or so. I'm not sure if the 200% bonus thing is working, but at least I am confident that his spawn is not totally borked. Just FYI offering what addition info I can.