>>Your main point seems to be that sex is determined by gametes, I agree. By that definition there are at least three sexes: those that produce sperm, those that produce eggs, and those that produce neither>>

That's an utterly stupid thing to say, and you know it. By your definition, children have no sex, and women in the menopause mysteriously go from being female to being "other". Any definition which classes five-year-old boys and menopausal women as belonging to the same "sex" has no value and can be rejected, because it doesn't explain how they can have a role in sexual reproduction without complex reassignments of sex in different directions at multiple points; at which point Occam's Razor applies.

If you troubled to read the article, you'd see that it talks about "which of the two gametes the body is organised to produce". (The word "organised" doesn't require some higher power to be true; it's an observation of the fact that DNA has the power to create functional organisms.) Five-year-old boys have bodies organised to produce sperm; menopausal women have bodies organised to produce ova; in both cases even though they don't produce those gametes at this time, we can be sure of their sex. This creates a descriptive framework in which we can understand when and why sexual reproduction works, which is the process through which evolution acts on humans. As this framework then describes and predicts everything that we see in humans, we use it as the basis for our understanding of inheritance, sex, and evolution.

You seem to somehow want to say that DSDs invalidate something, but your comment is too incoherent. On the embryology question, the embryo starts off as undifferentiated; it's not male or female. Differentiation starts a few weeks later.