Shatner's "Where No Man" novel in the interviews talks about it a bit but it also got discussed at conventions and by other folk who followed up on it.
http://www.beyondspock.de/interviews/print/shatner_where_no_man.php
He also stated that Roddenberry was quite serious about the fact it was a slam against women captains, though that was circumstances of the very specific time.
'In the last script - the last episode ever filmed, Turnabout Intruder, Kirk was in the body of Janice Lester. A lot of stories have spun off of that. What would happen if a person really could be of the opposite sex? - and so forth. What do you think would have happened if Kirk couldn't get back to his own body? How would Spock feel about that?'
Leonard chuckles. "Well, I haven't fantasized about it." He sobers.
"What is easier for me to deal with on that particular script is the knowledge that the writer was making a script in which his goal was to prove, quote, 'That women, although they claim equality, cannot really do things as well as, under certain circumstances, as a man - like the command function, for example. And it was a rather chauvinistic, clumsy handling of an interesting question. What he set out to prove was that this lady, given command of the ship, would blow it. That's really what the script was about. Just that simple. You see."
"Yeah," Bill agrees. "The problems were solved without really -"
Leonard cuts in, nodding "That's, what I was dealing with when we were shooting that show - the knowledge that that was the concept. And I rebelled against the concept. I was uncomfortable doing the whole show because I didn't believe in the concept.
"It's a very interesting question. But I think that the script didn't really deal with the question. The script set out to prove a preconceived personal prejudice. Didn't deal with - pretended to deal with the question, but didn't, you see. That's what I was pre-concerned with, primarily concerned with in doing that particular script."
For Nimoy to have been aware of that aspect at that time is extremely unusual. It's the same script - a Roddenberry story - that we ask Gene about and which he now sees as reflecting his errors of the time. The episode is criticized especially now for exactly what Nimoy names: not only does it set out to prove a point, but it does so with loaded dice. The woman who makes the switch is not a woman of Kirk's stature, but a resentful, crazed mass-murderer who steals Kirk's body. What she does can't prove much about the female of the species - unless one takes a very dim view of the nature of the female. Nor is it a test of how a normal female would command. A more interesting story could have been written around that question, and some have been.
What is still more interesting, however, is that Nimoy, Shatner, Roddenberry had to try to grapple with those questions then. And still do.
Wow
There's no denying the real intent of the script unless Nimoy and Shatner are lying.
At least one thing - Nimoy was against the intended message of the script.
I'm not sure that GRs intended bitter message came through though. Lester seemed to handle Kirk's job quite well - in reality too well to be realistic as someone who'd never worked on a Starship to actually know what to do as Captain, know everyone's name and what they're supposed to do enough to fool everyone.
It was only when she had to deal with Kirk that the insanity came out. Even then she was able to hold it together enough for security to consider executing all senior staff on board.
I think I'm going to go with the majority and gloss over this episode as Lester's mad ravings.