The characters don't have to be IN the movie. The movie however, should not make it impossible those characters can no longer be in the "history" of Star Trek. The movie can't CONTRADICT them, and it is.
So, did TOS "contradict" the existence of Dr. McCoy in the two episodes of TOS
besides WNMHGB in which McCoy did not appear (
What are Little Girls Made of? and
Errand of Mercy)?
What about the 12 various episodes in which Scotty did not appear, or the 27 episodes spread throughout the shows' 3-year run that Sulu was nowhere to be seen?
How is not having Mitchell on the bridge in this film any different than not even mentioning McCoy's name in
Errand of Mercy or
What are Little Girls Made Of?
...actually, on second thought it
IS in fact different since we know McCoy was part of the crew in those two episodes I mentioned, but we have no idea when Mitchell joined the crew. Mitchell could have joined the crew only one month before WNMHGB.