I thought I read elsewhere that 50A and 50K were missing some windows.
The adjoining aisle seats (50B and J) look from the photos to be staring right at the impressively capacious lavvies in CW upper deck - so might also be avoided.
A few other seats on the upper deck worry me: 59B and J look perilously close to bassinet locations at the front of WT+.
All in all, there are a few seats which might be less desirable, but I can't see any that stand out as must-haves.