'Non-binary' is such an imprecise category -
e.g this online definition
denoting, having, or relating to a gender identity that does not conform to traditional binary beliefs about gender, which indicate that all individuals are exclusively either male or female.
which doesn't make sense because it conflates 'gender' with the observable fact of being male or female, i.e. sex.
Except for the outliers who believe that sex is a spectrum, most people know and accept that they are either male, or female. So nobody is 'non-binary' as far as their biological sex is concerned [pace the tiny number of people who possibly have both sex characteristics who keep getting mentioned, but I don't know if there is medical evidence?].
You can declare yourself NB, but that does not change your biological status as exclusively male, or exclusively female.
Not 'conforming to traditional binary beliefs about gender' is something else altogether.
By definition GCers firmly reject the 'traditional binary beliefs about gender' - that's the 'C' in 'GC' - so I guess we could all justifiably call ourselves non-binar, if we wanted to.
Perhaps that's a good response to somebody who is making a bit too much of a fuss about being non-binary - a cheery 'Really? That's a coincidence, so am I!'