http://work.chron.com/gender-equality-issues-nursing-careers...
A bias would be if it incorrectly weighted "JOHN" and "nurse", and used the feminine for "John the nurse".
Assuming that lower-status professions are female and higher-status professions are male ("he is a doctor") when translating ungendered words is indeed a bias.
> the system will be right 93% of the time.
And "this person is a doctor, that person is a nurse" will be right 100% of the time.
It's also not wrong in the sense of generics: https://sites.ualberta.ca/~francisp/papers/GenericsIntro.pdf
The phrase "this person is a doctor" has a different meaning than "she is a doctor" - "she" and "he" refers to (I'm probably messing up the terminology here) contextually implicit person. "This person" does not.
Except when it produces "that person is a fine ship" or "John is that person's own person" or equally ridiculous things.