Earlier quoted context omitted.
Wouldn't the Reimer story support a naive version of biological sex moreso than an acceptance of gender identity?
It supports believing people about what their gender identity is instead of imposing it on them. The rate of attempted suicide in transgender people is over 40% if they are not socially supported. That rate drops to general population levels in trans people who have familial and community support when transitioning.
[0] http://williamsinstitute.law.ucla.edu/wp-content/uploads/AFS...