It's not very consistent and I need to think about my position some more, but I tend to be of the opinion that archive.org links are fair game unless one knows that the author specifically doesn't want their stories linked, and/or removed them deliberately.

Then again, I tend to get frustrated by people's misconceptions about the nature of the internet - specifically, that one doesn't require permission to link to publicly-posted material - so I tend to err the other way as a matter of principle. So I may not be giving fandom's specific cultural mores enough weight.