And by the same token, TOS could be progressive enough to include women on the ship, but not enough to put them in command positions. They could be portrayed as partners or subordinates of male officers but not superiors -- not unless they were exotic Others like Romulan commanders. Not because there was some formal policy statement against it, but just because it didn't occur to them. There were assumptions they made that we question when we look back on them, but that doesn't mean they questioned them. Maybe they didn't consciously object to the idea of women in command, but it didn't really occur to them to try it either.
It's interesting to consider that in TOS was there ever an occasion where a woman gave an order to a man on the Enterprise? I remember Rand tried to in 'Naked Time' or maybe she was trying to stop men sexually harrassing her.
I got the impression that Charlene Masters was in charge of the guys in her section (even though she didn't have the Lt bands on her uniform).
I watched TOS for the first time in the 70s and you sort of accepted the type of sexism that was in it them. At least they had some women aboard and some of them weren't secretaries, some were scientists, doctors and even Captains or First Officers (if you count aliens like Mara and the Romulan Commander).
Now I look back and choose to think they did have women captains and command crew - that we just didn't see them. LOL. At least the dialog in TOS didn't rule it out completely.