King Daniel Into Darkness wrote:
STVI makes it pretty clear the crew have been broken up for at least 3 years (McCoy didn't even know Sulu was a Captain - and the film opens with him returning from a 3-year mission!) and are reuniting for the peace mission.
That was the original idea, that the crew in retirement had to get back together one last time, but it was changed for one reason or another to be that the crew were going
to retire. Unfortunately, they didn't change some of the dialog they should have to reflect the change in the script (like McCoy wondering where Sulu is) so it made the whole thing confusing.