That might have been possible before FF.net decided to include a rule that said your story (if reported) could be removed if you posted a chapter that was just an author's note. Admittedly, like almost every other FF.net rule that only infrequently gets enforced (but when it does, it's in huge sweeps where hundreds, if not thousands, of fics are removed without notice or explanation), it's very frequently ignored, but some of us try to stick to the rules.
Have never taken time to read the rules. Never had to worry about them because I don't write. May be a good idea for me to do so. Would probably help me understand a ff.net writer predictaments ( I think that's spelled wrong).
I kinda see it like I would a job or meeting. Your not going to make it, it's nice to give a client or boss a warning. Not saying that writing fanfiction should be thought of as a job, but it's just nice to have a warning about what your planning. Shows that a writer cares about their readers and are willing to show their appreciation for a reader sticking with their story even if it's not something that should be taken severely like a writers person life.