Yes, but the crux of the issue is that as participants in a roleplaying game fiction, we take responsibility to author what those "stated otherwise" moments are.
A game in which I can use "shocking grasp" to separate hydrogen and oxygen from water is a very different game than one in which "water" is a fundamental essence of the universe.
I guess I'm just not seeing what the argument is about. Fictional universes make fictional alterations to the accepted reality. I just want a basic understanding of how the world works and what alterations have been made to our perceptions of reality so I don't have to constantly second guess what reality is in the fiction.