It never occurred to me before. And I certainly have no personal experience or academic authority to support such speculation. But, is it at all possible that a part of gender dysphoria is based on frustration over not feeling comfortable with traditional gender roles? In other words, could a child assigned female at birth's experience of being arbitrarily slighted or disadvantaged by societal norms contribute to that person's identification as male?
I've heard numerous anecdotes from trans women (friends and others) about being shocked to realize the privilege they've sacrificed in order to live their truth. I doubt that any of them had a latent desire to be treated as second-class citizens. But, when a young "tomboy" constantly feels less-than, powerless in a male-dominated world, might that not strengthen and reinforce the child's innate male identification?