You make the most sense. It's certainly not a resurgence of morality, nor do the leftists really care about women.
There's a political move going on. It's taking too big a toll among the highly visible elite to just to be a smokescreen for other events, or a breather from Tsunami Trump. Somebody or somebodies are making a play for power.
As I understand it, leftist women have been told for decades that they have to put up with abuse “for the Revolution.” Hillary Clinton was the icon for them: she was going to prove it was all worth it by winning the Presidency. But she failed.
Now they’re furious, and there are a lot of them: not only the ones in their 40s who give it up for the Cause for the last 20 years, but the ones in their 20s who came up with the “campus rape culture” thing to explain why they’re so miserable, when Hillary and her generation promised that free fornication would bring happiness and, above all, power.
You’re right: nobody knows how to throw a purge like the Left. There may, literally, be blood. Heads may roll.