DSDs are sex specific, though. You remain either male or female. If you have internal testes and are virilised through male puberty, then whatever your genitals look like, you are by definition a man. It's ableist and unpleasant to question that, based on cosmetics around the genitalia. Chromosomes and hormones make you a man or a woman, and the DSD one restricted to men or women.
Some people, due to medical limits in their region of birth, are wrongly assigned at birth as the visible genitals are incongruent with the hormonal and chromosomal facts. That doesn't change the reality, because words can't alter material fact.
I don't know if these boxers have a DSD or not. They may be male, they may be female. Jury is out. But a male with a medical condition affecting external genitals is still male. In fact, they have a condition that can only affect males.
There is no such thing as "intersex" in the sense of being hermaphrodite, and it's othering and ableist to claim otherwise. Again, no clue what the deal is with the boxers, but yes, DSDs exist - as sexed conditions. Depending on the DSD, if any, they may be male.