By morally explicit I mean a label which makes clear the writer's moral stance on the contents, rather than describing the events within the fic in a way the reader can judge for themself.

For example, "In this fic bad, evil things happen" vs. "This fic contains graphic descriptions of torture".

"Noncon (but not rape)" would be an oxymoron in regards to real life events (if we suppose sexual noncon is being referred to), but in fiction there are many ways we can imagine two characters having sex with one of them not consenting and the other proceeding in good faith - not to mention sex pollen and other noncon scenarios without any immoral agent. For me, whether a character I like is immorally raping someone or accidentally having nonconsensual sex with them makes a great difference. Nuance in language is a wonderful thing :-)