The policy states that no sexual images should be displayed in public places. Mark's keynote displayed sexual images in public places. There's nothing subjective whatsoever about the decision that followed, and Bruce's statement was related to the distinction between subjective and objective decision making. So on that basis, no, it wasn't used to oppress or treat anyone unfairly.
Mark's made no indication that he believes that the organisers' decision to apologise was unfair. In fact, without being required to in any way whatsoever, he made a personal apology. So even on the grounds that you're arguing, there's no evidence that anyone was oppressed or treated unfairly.