I never saw this as well. for further evidence I have watched the directors and writers commentary on trek 09. they never mentioned anything about uhura in the big 3 or even any big stuff. what they did was make it clear that kirk and spock are the stars of the show and everything revolved around them. that was what implied in the film.
I never saw uhura as part of a big 3 because she and spock were lovers. I never even thought of it as a big 3 , i feel pegg's scotty is actually the 3rd biggest character in the films. he has been the only character in the films not called kirk and spock to have his own type of back story, and own personal major plot point contributions to the films more so than uhura or bones.
