"Fanarts" only represent an idea, a creative expression on an artist's / fan's side. Unless it is a "film" or some sort, on its own it doesn't have a story to infringe the copyright of anything, and especially when the artist isn't using it for profitable gain*. I see no reason why FP should conform with Bethesda.
*While I say that, there ARE millions of artists profiting from parodies and fanarts, such as those on Newgrounds and DeviantArt. But they only every earn a penny or so for its works.