Do Kytons (chain devils) have sex organs? What about Type V demons? Are we supposed to imagine the Cathezar gestating? And was she laid as an egg, or born live? Was she born with her chains, or did she have to find them somewhere?
As I posted upthread, the whole thing doesn't support reasoning. The idea of the spawn of an unholy union is a trope, not an invitation to speculate about the process.
Support reasoning? No. It makes sense to me. It doesn't make sense to you. It's all made up. Neither choice is "right", it's just what we prefer.
If you don't like the idea of demons having sexual characteristics or gender . . . okay, that's fine. But some folks do, and it's not because we are ignoring "reason". It's supported in past D&D lore, and isn't really addressed clearly in 5E lore. Should it be? Eh, I'm not overly concerned in the D&D team ever addresses this directly, why should they?
All of the questions above . . . do kytons or other demons have sex organs, would the Cathezar gestated for a time in the womb or laid as an egg, was she born with chains or acquire them in some other way . . . all of those are interesting questions, IMO. As a DM or creator, I just might dive into all of that backstory for the Cathezar. Or I might not worry about it all that much. Again, personal preference.
It predates Planescape: Eldritch Wizardry and the AD&D MM both describe Type V demons as female.
And according to another poster, Mariliths are not mono-gendered in Planescape:
Yes, mariliths being female predates Planescape, it is also lore within the Planescape line. Let's quibble some more on that minor detail.
In past D&D lore . . . which is inconsistent between supplements . . . demons as a category could have gendered and physiological traits and needs, including sexuality. But mariliths as a type of demon were all female in their true form, and they have always been depicted as female . . . until 2025. Which is why we are all arguing about
very important things.