It’s an emotional reaction rooted in transphobia, not a logical one.

But to my point of a loss of expectations, that part is like when kids don’t turn out how their parents had hoped. To use another cliche, when their kid who was going to be a doctor runs off to do art instead.

Those parents that love unconditionally will let go of those expectations, learn to love their kid for who they actually are, and in time appreciate their transition as a period of growth rather than loss.