I think it's one of those 'umbrella' terms, to try to include those who are genderqueer, or are transitioning but don't necessarily identify as male. I'll be honest, I still don't know a lot about correct trans-terminology. I still occasionally say 'bio' as opposed to 'cis', since it's never struck me as offensive, so I'm far from PC, ha. I don't really spend a lot of time in queer or trans space though in real life, I'm sure if I did I'd be more educated about it.