For starters, I don't think billionaires spend much time in public restrooms, if any at all. Secondly, I'm certain she also doesn't want trans men using women's bathrooms either. She's trying to create a situation in which trans people can't use public restrooms, which means not being able to work, which means not being able to live. This is erasure, and she's willing to sacrifice the rights of cisgendered women to achieve it.