Ok, thanks I went and read some more seems about that's an accurate description of the reason he's being banned.
on edit: I guess from what I read there it seems he's saying being male and female are biological categories, but he does not specify what kind of category transexuality would fall under, that is to say from looking at just that page not sure if he has said transexuality does not exist, only that it must be something different than the male and female categories. Which from what he writes seems that he wants these terms to mean 'born with male organs' and 'born with female organs' respectively.