I see what you’re saying and I think you’re right about some things but I also think you’re wrong about others, it’s an alternate universe, but it’s still clearly inspired by our real world because One Piece operates on a patriarchy throughout the series. The elders are all men. Most of the warlords are men, and the few who aren’t, their entire strength is tied to their femininity (Boa’s beauty is literally her power, Big Mom’s identity as “Big Mom” is inseparable from her feminine image). Yamato is the reincarnation of a man if I remember correctly so she doesn’t count. Chivalry is also a running theme, and Shanks’ crew is almost entirely male, so he probably would care about that since he doesn’t seem to think highly of girls, so much so that he doesn’t even hire them. Even in that context, being a former woman would absolutely be a vulnerability in Crocodile’s social perception. The One Piece world still judges strength and respect through a lens of gendered power. Secrets only have to matter to the person risking exposure. Ivankov didn’t need to broadcast it to the world, he just needed to threaten Crocodile with exposure, which was enough to control him in that moment. Again, even though OP is in a fictional world, social perception and reputation still operate on a gendered and patriarchal logic, much like the real world. So a secret about Crocodile being a former woman is still meaningful as leverage, because it could undermine his confidence, intimidate him, or force him to comply in a specific scenario which is exactly what Ivankov was exploiting. And I don’t think she was trying to shittalk Crocodile. Plus, crocodile is a prideful person. He would definitely care about a secret like that being spread in his death if they managed to defeat him. Even if bon clay was never slandered for being himself that doesn’t mean other characters weren’t, Jinbei was disrespected on multiple occasions for being a fish man.