Do you happen to have a link to the article?
https://dellcomicfan.blogspot.com/2012/03/rare-whitman-comics-from-aug-to-dec.htmlIt was a question asked solely out of curiosity, partly based on the Whitman rarities due to a nonstandard distribution. There are lost movies due to deteriorating stock and, for silver nitrate prints, for recycling the silver from them. Movies didn't have have large consumer distribution, so it's not quite the same. Movies tended to be publicized, so the lost ones are mostly known. Comics got less public notice. About the only way a loss would be noticed if there were other comics that referred to it or there was a break in numbering.
I would guess that most of what we know about what comics were published is based on what comics exist. If no comic reader saved a one-shot title, there may not be any knowledge that it was ever published. I don't know if copyright records can be easily searched by publisher. It's very possible that there are many more lost comics for which there simply isn't a record of their existence. With all the comic book publishers that disappeared over the decades, many probably left no written records of their output.
Where did you find a cover for Sharp Comics? If it was advertised in a comic, it probably was published, but may not have. Amazing Fantasy #16 was advertised in #15, but never published. It's mentioned in a blurb at the bottom of the last page of the Spider-Man's story and also mentioned in what's titled as a Fan Page in the comic: "As you can see, we are introducing one of the most unusual new fantasy characters of all time--The SPIDERMAN, who will appear every month in AMAZING. Perhaps, if your letters request it, we will make his stories even longer, or have TWO Spiderman stories per issue." This goes to show how faulty Stan Lee's memory is because he's often said that Spider-Man was published in that comic because it was going to be the last issue.
I'd also quibble with Lost Media's definition of "lost." I'm more interested in what was published and can no longer be found than in what was created, but not published. That's akin to saying that there's a lost Star Wars movie starring Kurt Russell and William Katt or the myriad numbers of screenplays that were never turned into movies.
There are tons of comics that were made, but never published--most of which we'll never know about because the pages were destroyed. These were comic stories that were commissioned and not used either because the editor didn't think they were good enough or the title was canceled. There's the story of Atlas/Marvel where Martin Goodman found a closet of stories that had not been published and let go artists and published the unused pages. A similar thing happened at DC's romance department and resulted in John Romita not getting enough work to support himself while the unused work was published. That led him going to work at Marvel; with Gene Colan following from DC a short time later for similar reasons. It's odd that two of Marvel's top superhero artists weren't given superheroes to draw when they were working at DC. Jack Kirby was blacklisted at DC over a financial dispute with an editor that helped him land a comic strip. That resulted him going to work for Marvel. Marvel owes its early success to artists DC stopped working with.