I tend to regard discussion of authorial intent as something akin to Lies Told To Children, when it comes to literary analysis. In that beyond a certain point it's not really relevant (except maybe as an entertaining footnote), but it's often used as an entry point to teaching literary criticism, as something that young readers can hook onto and understand better than lit crit as a whole.

Which means that it's probably still appropriate in high school, but I would seriously side-eye a college professor who taught any sort of literature class with an emphasis on what the author "meant" or the symbolism they "put in". (I sometimes think that they still teach The Scarlet Letter in high school purely because the author stands up and goes LOOK AT MY SYMBOLISM BOY HOWDY right in the first chapter, which makes it an easy version of the Lies to point to and teach.)