Gender reassignment surgery is pretty drastic. As is taking hormones. I think there's a big difference between the normal discomfort most people feel with regards to their bodies, and what people with gender dysphoria experience. Yes, it's impossible for them to TRULY know how the opposite sex feels, but I'm willing to accept that someone who wants to remove their penis has a real problem being in a male body, and that they would have much less of a problem being in a female body.
you describe a man who has chosen to have his body surgically altered to resemble and function as- inasmuch as is possible- a woman's body. There is nothing wrong with that, and a person who has reached the age of majority should not be prohibited from doing so.
The man you describe is still a man, however. A Trans-woman more accurately put, but a man nonetheless.
A hypothetical analogy.
Suppose some unethical doctors somewhere took a chimpanzee and altered it through chemical and surgical means to resemble a human in all external and internal respects to the extent of their ability.
Would it then be human?
You might respond that it would lack the cognitive ability to qualify- yet we do not consider severely cognitively impaired individuals to be anything other than human- so that line of argument seems closed In much the same way that undeveloped sexual characteristics- or the onset of menopause- do not cause men or women to be considered anything other than Men and Women.
My part you can guess of course, since I made up the hypothetical. The Chimpanzee, despite the manpulatin of its body to make it more human-like, remains a chimpanzee as it does not meet the three requirements to be a Woman: Adulthood, Femaleness, and Humanity.
A trans person- regardless of the surgical and chemical treatments that might be available to them- does not become the opposite sex because of those alterations, even when those alterations are to conform to arbitrary behavioral characteristics as well as physical ones. But they remain female or male based upon their biology, not the alterations made to it. When a trans man asserts they are simply put "a man" they are missing one of the three qualifying aspects of that label (maleness) the same way the experimental animal in the analogy is missing one of the three characteristics (humanness)