I had a brief look and can't really find any detailed empirical work on the matter. The paper by Gray cited in the article does not really have much empirical

I had a brief look and can't really find any detailed empirical work on the matter. The paper by Gray cited in the article does not really have much empirical work behind it - but is more about identifying the concept of the anti-fan as such and acting as a call to action for the research that is needed. Given that the concept is relatively new, it may be extremely difficult to identify historical records of genuine anti-fans back in the day, since many may not have known that this is the sort of practice they were engaged in.