There should be an "Unknown Media" section to the site.

Well it depends on what you'd define as "Unknown Media", since some people can define that as being pieces of media that is thought to exist but there's no proof it does exist, since most pieces of lost media listed on the wiki have proof that they exist or have existed at some point. Granted this is the kind of stuff that is often seen in the form of creepypastas, as seen with Crybaby Lane before it was found, though people are often familiar with the cliches that "lost episode" creepypastas tend to have at this point, which disproves them even more so.

As for what the first post says, this is rather common on the internet since at many times I find someone post an image or video on Tumblr that's obviously from some kid's show and the original post does not give a source in the tags, and I'm the kind of person who likes to cite my sources.