What reputable psychological organization defines gender dysphoria as a mental illness? None of them do. And how are trans women male?
When hormones are switched from male levels to female levels, the Voice [1], secondary sex characteristics (outside appearance)[2], muscle mass[3], body fat[4], body hair[5], many medical traits like urinary acid[7] and much much more we don’t understand change from masculine to feminine or feminine to masculine. There are even a lot of psychological changes such as in aggression[6].
They don't have every biological trait a woman possesses, but they have most of them. Clearly their biological sex should be considered intersex, and you always call an intersex woman a woman.
[1] (a trans man talks with his new voice) https://www.youtube.com/watch?v=xU1GbFXoHKc
[2] Look at all of these timelines that show the changes in appearance:
[3] This trans man is able to compete at the highest level of his sport, the duathalon world championship, among men because of the muscle mass he gained from testosterone:
https://pbs.twimg.com/profile_images/552793645544259585/zK9KMRu1.jpeg
https://en.wikipedia.org/wiki/Chris_Mosier
More trans men with masculine muscle mass:
[5] Here are some FtM beards: https://www.google.com/search?q=FtM+beard&hl=en&biw=1024&bih=632&site=webhp&source=lnms&tbm=isch&sa=X&ved=0CAYQ_AUoAWoVChMIyczSsIrmxwIVg5mICh2bXAwT
[6] Use ctrl F “It has been suggested” or scroll to the “It has been suggested” paragraph:
http://www.iiav.nl/ezines/web/ijt/97-03/numbers/symposion/ijtvo05no03_02.htm
