A few years ago, I remember hearing reactionary podcasters panicking about trans identity propagating by "social contagion" {their phrase}. The word "contagion" sets up an awful frame around this. I think instead you could come at this from an angle that recognises that there is a kind of social and internalised Overton window, a set of ideas that people are willing to express, or even allow themselves to think. As we increasingly see people living good full lives expressing and owning aspects of themselves that had once been heavily stigmatised - there may be a dynamic beyond just better diagnosis - there may be an uptick of people willing to be more honest about an aspect of themselves that they may otherwise have sought to hide or suppress, others might have been able to avoid even self-awareness. If that is the case - just as there will never be a person who matches the reference human genome - there may be no upper limit to the fraction of people who find some aspect of themselves that extends outside the venn diagram circle of neurotypical.