Hello, I just created a very customizable MessageBox template for the French wiki, code and examples are here : https://kagerouproject.fandom.com/fr/wiki/Mod%C3%A8le:MessageBox (Admins, if you wish to use them, I can localize the TemplateData into English, you can of course reuse it! I can also help if you're interested to follow the design of french wiki's homepage).
Okay, so let's talk about the main subject.
I tested this model for the first time on the Ayano's theory of happiness page, in order to display a prevention message about lyrics that may express suicidal intentions and thus take a step back :
While messing around and trying this module, I just realized we do need to warn if there is a questionable content such as suicide, just like the templates used in the Vocaloid wiki (https://vocaloid.fandom.com/wiki/Template:Questionable). Teens don't necessarily have enough free will and may think that committing a suicide is a good thing, when it is not at all...
Finally, what do you think about the need to add messages box on sensitive pages in the english wiki ?