Re: Was the Enterprise A actually the Yorktown?
It was probably in one of his hundreds of random "I think we should..." gripe letters to the studio that he wrote during filming. IIRC, he didn't much of how any of the movies after TMP were written and went to great lengths to be a burr in the sides of the other writers, directors and producers working on them. I think by this time the studio relegated him to the emeritus status of "Executive Consultant", or something, and he had been fighting a losing battle for control over the property for years. I think he lightened the pressure over the films once he got TNG, but he still sniped at them on occasion when he thought the situation warranted it. Shatner's "Movie Memories" went into some detail about it.
I may appear unoccupied to you, but at the molecular level, I'm really quite busy.