Don't know about the last sentence.  
People have the right to self-identify.  Hmmm?  Sure, as an adult you have a right to be whoever you want to be.  Don't expect government issued id papers to conform to whatever you believe is true about you (e.g.: Hey, I am way better looking than my driver's license picture.  No fair!!!).  Those identity papers are meant to help unambiguously identify you.  One clear identifier is biological sex and so that will not go away.  "Gender" is more difficult as that is about what is happening in your head and so may or may not help with identity on such documents.  Please feel free to dive in on how to identify gender (on a continuum?) on an identity paper.  Identity documents will look at physically identifiable facts (sex, height, eye colour, hair colour, fingerprint, blood type, DNA, etc...).  I see a very limited role for gender in this.