That’s because each of the listed examples don’t include explicit game features that players can abuse and spread inappropriate content. In this case, players are held accountable for their own actions as normally expected. There are no features you can use to the degree of spreading inappropriate content within the playerbase.
Anyway, this subdiscussion is getting a bit off topic from school maps in shooter games. I simply wanted to clarify that developers are, to an extent, responsible for the behaviour of their players and will get moderated if its possible to abuse a feature and expose players to inappropriate content. If you’ve mitigated this or don’t have any abusable venues, you are okay.