They would continue to be male, forever. "Female" is a sex, not merely a gender identity. At birth, nobody is "assigning" genders to you, they are attempting t

They would continue to be male, forever. "Female" is a sex, not merely a gender identity. At birth, nobody is "assigning" genders to you, they are attempting to observe your sex from primary sex characteristics. If they see vulva, they are observing a female; if they see penis/scrotum, they are observing a male. While there are edge cases, it is generally pretty simple.