I have to be honest, I am hot and cold on the issue of warnings on fics. As a writer, I don't like the process of spoiling major events of the story because there is potentially a reader who will blame me if they are "triggered". I buy books on amazon all the time that have rape and incest and incest rape and zombie incest rape etc etc all the time... and there are no warnings on these books and if someone pulled a "I was *triggered* by the rape scene in that book and nearly killed myself and my roommate and was hospitalized for three days, how dare you not warn me!!!" on the author.... no one would point fingers at the author for not warning.

Warnings are a courtesy on fanfiction, but its entirely possible your author in question is simply checking the box, so to speak, because it gets her off the hook and she doesn't have to reveal a major plot point. If some person reads the story and has a traumatizing triggering event - well, she put a warning so buyers beware.

*I'm not trying to make light of people who have "triggers" but it is not my role as an author to protect the reader and if someone has such a severe issue with say, reading about a rape, that it really does cause a two day hospitalization upon reading it - then that person needs to self advocate and ask authors whats in their fic. I can't know everyone's triggers.