Sex Shaming & Status War
The road to ending “slut shaming” of women probably goes through the town of “destroy the norm of giving men status for being sexually successful, and of treating male virgins as disgusting losers”.
I say this because I think some of the desire to enforce sex norms on women relates to the nature of sexual access as a status good for men.
If a low-partner man gets into a relationship with a high-partner woman, he is considered lower status for it, under multiple frameworks. Under a “promiscuous women are low-value” framework, it lowers his value by suggesting he had to ‘settle’ for a woman other men could extract sex from but didn’t consider worthy of commitment. Under a “anyone having a high partner count means they are high-value” framework, it suggests that the woman is higher value than he is (which is risky if men are judged more on status than women are), and that the way for him to raise his value is to have lots of meaningless sex with lots of people.
If a low-partner man and a high-partner man are in the same community, the low-partner man is lower status than the high-partner man is, since masculinity is contingent on success, and success with women is counted as one category of success. (In fact, one of the socially damaging aspects of virginity / lower partner count is that it is considered “unmasculine”.)
This creates a strong motivation for status war. If low-partner men can attack promiscuity in women, they can create a situation where women have partner counts closer to their own. Failing that, they can lower the status of such women so that they’re at least not higher status than themselves.
Unless their sexual success is decoupled from their social status, men will always have a motivation to wage status war through “slut shaming”.
The way to alter the status of high-partner men is not through straight men themselves, since their value in this respect is conferred by women. (Low-partner men are already low status, so they have less social power to alter these very norms.) It’s through the actions of women.
One way to do this is for women to start treating promiscuous men the way promiscuous women were treated in the past. If women started treating high-partner men like hot potatoes that are disgusting, low-status (like male virgins are now), and aren’t worthy of sex (not just commitment, as getting a woman to commit isn’t considered special), it would radically alter the status dynamic in male communities.
Another possibility is if commitment from women somehow became more difficult to get, and thus was considered special and more valuable than sex, but it’s unclear under what conditions this would emerge as a stable equilibrium. Current conditions don’t favor it or any obvious paths to it. The traditional norm is the opposite - women trade sex to get commitment. If this could be changed, it would increase the status of a man the woman finally ‘settled’ for. (It appears to be true in the opposite direction currently.)
Another way to do it is to treat low-partner and high-partner men the same in a very noticeable way so that men will start internalizing that being high-partner isn’t the same as getting the “approval from women” they need to prove their masculinity and raise their status. This doesn’t mean in fields unrelated to sex. The status comes from sex, so they have to be treated as equally sexually desirable, perhaps even the virgins.
All of these courses of action have their own problems. Depending on the balance of nature vs nurture, some or all of them may not even be feasible. They may do secondary damage. They may just not be enjoyable to a lot of people.

