There is literally no nerdy reason to insist that Gary Mitchell ever appear, or if he does, that Elizabeth Dehner also appears. This Kirk has had a different life from birth
, he may have never met Mitchell... and more to the point, it's already a massie coincidence that so many of the old Star Trek crew just happen to join the Enterprise in this time. There's no reason that massive coincidences in ship rosters continue
to happen - it's a big Starfleet out there, and a couple of decades of divergent history and many people who were born in one universe wouldn't be born in the other, there's people who survived acts that killed them in the other universe or vice versa (George Kirk and most Vulcans good examples there).
Taking the alternate universe explanation given in the first film, and given that we've had over twenty years of divergence from the timeline, the Abrams team have sizeable leeway to do wahtever the hell they want with the story without ever running into anything we could fairly exclaim was a continuity snafu.
This is what I call the "Yippie-ki-yay effect". No one would remember that phrase from Die Hard had it not been repeated in Die Hard 2.
The Wrath of Khan is generally regarded as one of the best (if not the
best) Star Trek film, and elements of it - like Kirk screaming KHAAAAAAAN - are still recognizable, if ridiculed, parts of pop culture. Abrams' new film took more than a few cues from Khan, particularly its use of the Kobayashi Maru test.
I have difficulty recalling what Die Hard 2 is even about, beyond being another Die Hard. It may be true that DH2 solidified the pop culture lexicon from the first movie, but TWOK pretty much defined
the pop culture image of Khan - even in Trekkie circles, one's more apt to have someone quote the theatrically vengeance driven Khan of the movie rather than the smug woman abuser of the episode.