I was recently at a theatre event where notices had been stuck over what used to be the ladies and the gents.
The notices used the combined male and female symbol together with an explanation that the toilets behind one consisted of x cubicles and y urinals and the other consisted of z cubicles and no urinals. Patrons were encouraged to use the facilities which most closely matched their gender identity. Gender neutral facilities are also available if requested.
I don't know what or where the gender neutral facilities were - presumably the accessible toilets.
I am not sure what criteria would apply if one were to request to use the gender neutral facilities. In theory most of the regular posters here could ask - although I suppose it is meant for trans people who are not comfortable in the loos usually used by the opposite biological sex.