Apparently even Nissan got bored of the Altima coupe. The car didn't change at all for the 2013 model year, and Wards Auto reports it's off the 2014 lineup.
Admittedly, it is possible that Nissan had no intention of cancelling the two-door, and simply just forgot it existed, like the rest of the world.
Nissan Gives Up On The Altima Coupe