>>36973218What a coincidence, I'm also a writer. And I know all about Chekhov's Gun just like you're referencing here.
But I also know that not every detail in a story has to be correct or true. Actually, adding false information can be good. Making myths that aren't confirmed to be true can contribute to worldbuilding and realism by making it look like the characters have beliefs that aren't necessarily factual, just like most real life myths. It also makes for a more interesting story if there are some mysteries like legends and myths that aren't confirmed or denied by facts/evidence.
So I think it's better to write some things that aren't explicitly true, and the Sinnoh myth can be one example. It totally could be real, but the fact that it's explicitly called a "folk story" means it should be taken with a grain of salt. I'm not saying it must be incorrect, but I also think it's wrong to assume it must be correct just because it was written down. Out-of-universe, it could have been included for the sake of worldbuilding, like I mentioned before, as opposed to being an accurate history lesson. In-universe, we don't know if the author was writing down how things really were, or just making up an interesting story, or maybe even trying to tell some kind of moral lesson like Aesop.
I don't know if I got my point across, but those are my thoughts.