Earlier quoted context omitted.
Death of the Author. One of the important elements here is the extent to which materially it matters. If I buy a book Lovecraft wrote a hundred years ago the money isn't going to end up diverted to support the "patriots" who want to intimidate my neighbours, whereas when I buy a Harry Potter box set for a relative you can bet that Rowling's share will help fund "Gender Critical" movements trying to make life worse fo…
You're conflating whether one should feel guilty for supporting an author, and whether the author's speech outside a work matters to understand its intended meaning. The latter is the actual Death of the author , the former is usually called Death of the author by people who want to separate themselves from the authors they know they can be judged for supporting.
Also, AIUI Death of the Author is not about whether their beliefs mattered to understand the intended meaning, but instead whether "intended meaning" is even a thing anyway. No need to understand it if it doesn't exist. I prefer in other contexts not to try to guess intentions when I can instead look at the effects and it seems to me our law and practice agree.
Notice for example that while proving attempted murder requires that you wanted the victim to die, murder does not. The fact that they are dead satisfies this aspect of the crime, you aren't innocent of murder just because you didn't intend that the victim would die.