The current showcase rules miss the fact that you cannot repost a project (as addressed in #1492945499681067240).
Additionally, there have been multiple instances of people not putting the AI-assisted tag on their post; it only kind of hints that it is required, a bit at the top and then again at the bottom of the rules.
IMO, it would be best to more directly state the rules on AI, as well as reposting rules. I suspect people don't read the full rules due to their length (even though it's really not that long).