It's an endemic issue on wikipedia, and even editing wouldn't fix this one instance, since someone can (and demonstrably already has) remove whatever you add later on. The issue is wikipedias preference for "deletionism", removing perfectly correct information for no particularly good reason. It's especially pernicious when it comes to short articles, which tend to get deleted with impunity, and redirected to sections of articles, which later get renamed, destroying the link, or removed altogether. Nothing can be done by any individual to fix this issue, since it comes from a wikipedia wide policy, which unfortunately is not one of the things that "anyone can edit".
I agree with most of what you wrote, but unless you can demonstrate that someone actually added CachyOS to the "Arch Linux-based" on the "List of Linux distributions" page and it was later removed, I'm not sure how much it matters how Wikipedia generally works.