UPDATE: Well, the passenger side wiper was still back-ordered. I checked the part chart, and the factory replacement size was 500mm for drivers side (in-stock with the u-hook adapter) and 458mm for passengers side.
Well, they had a 450mm screw-on with the u-hook adapter on the wiper rack.
I figure the car will not miss the 8mm difference.
Parts guy cancelled the back order and swapped out the wiper for me.