LJ has responded to the queries (some of them, anyway) over at this post. Art that depicts characters whom LJ Abuse thinks are underage is now verboten, and the journals posting such content can be permanently suspended with no warning (and no refunds, for paid customers). Whether the art was locked or not makes no difference.

Their response to questions about whether fics that depict underaged characters in sexual activity were also prohibited was so vague that you could drive a truck through that loophole. And given their recent history, I'd guess it's only a matter of time before they start applying this rule to fiction, as well.

I had two stories that showed characters who were (or could be interpreted as) underage. I've edited one of them to clarify the age, and the other has been moved to GJ, and the post here links to that other post. But so far, LJ is not responding to repeated queries about whether "prohibited" content can be linked to, if posted elsewhere. Who knows?

With this new "clarification," I'd say that almost every HP pairing is shafted (except perhaps Dumbledore/Minerva or Dumbledore/Grindelwald, assuming that the story doesn't take them back to their teenage years in an AU setting). Because substantial numbers of the stories and art created for almost every other HP pairing do fall into that underage category, for at least one of the people involved.

They're trying to limit us to either gen, or post-Hogwarts stories.

We need to move somewhere else, my dears. In the meantime, I'd consider posting R or NC 17 art or stories elsewhere, and linking to them from your LJ.