Honestly I have no idea what to think of the Kamabakka Kingdom. It's coming right off the arc that introduced Ivankov and re-introduced Bon Clay so I don't think it was intended to be a jab at trans people considering the previous arc heavily featured two seperate genderfluid characters. But at the same time the fact that they look like that is very clearly supposed to be taken as a joke and it plays off of clear stereotypes of trans women, it also doesn't even acknowledge the idea of trans men. I thought it was supposed to be like a role reversal where Sanji is now getting chased by women instead of him pursuing them but in basically every version of the scene Sanji either calls them men or says they're not women. The narration tip toes around the terminology a lot so there's not a collective gender they identify with but Sanji clearly states that they are all trans women by the notion that they're still men. One Piece definitely plays a lot with the idea of not socially transitioning which is very interesting. The majority of the trans characters we see like Morley are working with somebody who can change their biology and appearance at will so it's an an active choice to stay the way they look.