Sod it, I've percolated this long enough. Behold my not-hugely-thought-out take on the subject as it stands for now.
It appears that the two largest (and increasing) groups seeing sex transition are teenaged girls and middle aged men. In each case, I really wonder if the prevalence of porn in society is partly/mostly responsible?
Teen girls (and boys) are increasingly exposed, unwillingly or no, to porn. Obviously this porn is becoming more extreme, degrading and disturbing (c.f. Reddit) and very easily viewable. Dr. Gail Dines has a really interesting lecture about porn and describes the effect on first experiences of such material on young teens as a trauma response. She also points out that there is no such thing as 'soft core porn' anymore because it has been assimilated into popular culture (for a most recent example, I would include the video of WAP by Cardi B).
Given that many girls will possibly repeatedly be shown extreme porn at a very impressionable age by their peers, is it any wonder that they would opt out of their sex if they could? Who would want to be viewed this way if they could help it? If their most often observed type of sex between men and women includes being slapped, choked and degraded, what girl would happily choose to enter such a relationship?
In the recent Newsnight regarding the Tavistock, there were a fair number of parents reported seeking transition for their children who it seemed could be reasonably summed up with the feeling of "I'd rather my child were trans than gay". Within the GC community of those who have experience with these teens, agreement that there is a strong background of homophobia as a motivator for parents seeking transition for their children.
On the other side, middle aged men have grown older in an internet porn age and become habituated to this more and more extreme and niche types of porn (again, see Reddit). On this thread, we are well aware of AGPs as distinct to men with genuine dysphoria (you might expect dysphoria to emerge a lot earlier in life). How many of these men/AGPS, I really wonder have a "sissy" kink as a result of the internet porn age?
Besides all the other innumerable problems with the porn industry, especially with regard the treatment and abuse of children and young women, what chance have kids of either sex got to grow up without developing psychological and emotional problems from the onslaught of porn and the echo-chamber of forums telling then that this is normal?
The Dr Dines video is an hour 20 but it flew for me, really interesting despite being missing the slides.