But do you think IS people would really attend what seems to have been a TQ+ protest to demand IS rights in that way?
That's a very good question, Shedbuilder. Adults with DSDs are of course very welcome to identify as trans, or non-binary, or a or queer, whatever. But, as someone who has met hundreds of people with DSDs, I would say the activist, queer types are the tip of the iceberg, and the vast majority of us are quite boring and live incognito with white picket fences.
Some problems arise with the use of intersex to refer to an identity instead of a family of medical conditions. As the link shared by Purgatory shows, medical intervention on (some) kids with DSDs is a huge, serious and urgent problem - and has been urgent for 25 years, when the then ISNA brought this to wide attention. The increasingly vocal and agressive calls to equate DSDs with a third sex and trans and an exotic curiosity is taking the progress made over 20 years backwards, by breaking the trust and weakening the links between parents, the medical experts and adults who can provide their experience.
I really don't think the needs of children with medical care needs is best served by posters asking for human rights displayed in the way they are on the photo shared by the OP. Even if the poster is held by a person with a diagnosed IS condition, who may have their own baggage of poor medical intervention that is driving them to activism.
And then there is the issue that with intersex being an identity, people who are not IS are misrepresenting the IS population. I don't take at face value anyone's use of intersex keyword in their profile.