Know plenty of people that have removed their rear wipers on various cars in various states including NY, PA, NJ, CT, MA, etc and no trouble from authorities and passing inspection...
For me, I couldn't care less about the rear wiper as the rear window is not a heavy stagnation point. That is due to the rear spoiler (yes it is actually functional) eliminating high pressure from the rear window area. Though I would like to keep the wiper for winter when snow falls and I am traveling at a low speed.