Back to the point I was making: BI didn't choose Oxman due to her academic position. They chose her because she is the wife of Bill Ackman.
It's a good tactic! But let's assume Oxman and Gay are equal on both scholarly output and extent of plagiarism.
Removing Gay (who was President of the world's most famous university) seems like it moves things forward. Bringing Oxman into it seems like it's aimed at halting that progress. BI is engaged in whataboutism. If they were trying to show how pervasive plagiarism is, they could have chosen a current academic, ideally one with a senior position at a famous university.