I find it's a lot less complicated to accept that the "Uhura don't know Klingon" gag was one of the dumber things ever concocted in the history of Trek and simply forget it ever happened. Actually, that works nicely for most of TUC.
It's like McCoy not knowing Klingon anatomy when he tries to save Gorkon's life, when we now know that Starfleet had at least somewhat detailed scans and information about Klingon physiology as far back as the crash landing of Klaang in Oklahoma in 2151 and it's possible that the Vulcans provided additional knowledge about the Empire as they saw fit. McCoy and the 1701 and 1701-A crews had frequent run-ins with Klingons over the course of the decades and were often within tricorder scanning range of them.
McCoy not knowing how to save Gorkon in TUC is along the lines of Uhura not knowing how to speak any Klingon - it works in the context of that one film and its assassination and prison break storyline, but beyond that it falls into pretty silly territory and would be dismissed otherwise.