I think the author here misrepresented the JK Rowling thing quite a bit. The idea is not to "scour" her texts for hidden anti-trans sentiment. The idea is that Rowling makes money off of selling her books and has built an empire, and the resultant power is now used by her as a platform to propagate anti-trans speech. Quite a different issue and also quite novel (pun unintended). Death of the Author is a concurrently operating, but in my opinion separate, question.