After applying the updates, I'm getting a whole bunch of these error messages:
MMAP:loadMap: 5712226.mmtile was built with generator v9, expected v12
Could not load MMAP name:Northrend, id:571, x:22, y:26 (mmap rep.: x:22, y:26)
I haven't had any luck finding the v12 generator to extract them myself.