I'm genuinely confused with how the disorder can make reference to things like "toys assigned to their gender" when even I admit that's somewhat a social construct. I mean what if a person is born female and wants to become a trans-man yet still wants to wear dresses and play with dolls just because that's what (s)he finds appealing? They'd still be trans-gender, right?
since kids aren't the best at introspection, i'm assuming these are just general indicators that something deeper might be going on. that's probably why you need so many of them going on for so long in order to get a diagnosis. still, the roots of trans issues and gender dysphoria are definitely related in a non-insignificant way to the social construction of gender
you can look at the diagnosis criteria for adults/adolescents for comparison (here's the page this stuff comes from again
https://www.psychiatry.org/patients-families/gender-dysphoria/what-is-gender-dysphoria )
obviously, these are much more complex ideas that kids would have a harder time asking themselves and being sure of, but they are more definite and provide much greater assurance, so only two are necessary
also note that both require actual distress and harm to normal function to be present in conjunction with these symptoms
