Genuine question, just a thought-
If you were single, and then met the most charismatic man, and decided that you'd like to sleep with him that night, do you think you have the right to know whether they have penis or a vagina, before it's staring by you in the face, or not? I think you do.
There is far more to sexuality and sexual attraction than someone's genitalia, but it is the primary sexual characteristic that defines whether you are a man or a woman.
I'm bisexual, but if I came home with a 'man' who I then discovered was biologically female, I wouldn't carry on and just think, "I'm bi, I can work with that".
I'd feel deceived, and totally vulnerable and furious to have been led into a situation unprepared for what was happening.
A similar thing has happened to this beautcian. She's not qualified to work with male genitalia. She was not expecting to see male genitalia when performing a women's beauty treatment.