I'm completely with you right until the phrase "and disproportionately affects a certain protected class". What's a protected class and how does it differ from any other class?
Protected class is what you can't fire/refuse to hire someone for. Race, religion, etc. You can refuse to hire people who don't wear a suit to an interview. "People who don't wear suits to interviews" is certainly a class, but not protected. You can't refuse to hire black people, because race is a protected class.
But what if there is a significant correlation between protected and unprotected class? Like, what if black people are much less likely to wear a suit?
Protected class usually refers to groups protected against discrimination by law.