I'd interpret the original statement as "tests which don't matter" and "documentation nobody will ever read", the ones which only exist because someone said they _have_ to, and nobody's ever going to check them as long as they exist (like a README.md in one my main work projects I came back to after temporarily being reassigned to another project - previously it only had setup instructions, now: filled with irrelevent slop, never to be read, like "here is a list of the dependencies we use and a summary of each of their descriptions!").
Doing either of them _well_ - the way you do when you actually care about them and they actually matter - is still so far beyond LLMs. Good documentation and good tests are such a differentiator.