I mean it basically already is a rule, as users known to be under 13 get suspended until it can be certain that they’re 13 or older, but that’s on me for using unclear terminology when I meant “~pg13”.
Okay, so assuming you also had “~pg13” in mind, I’m not exactly certain as to how difficult implementing and enforcing such a rule would be, however I can see reasons for keeping it as a social agreement and a sort of a standard that all users should strive towards. These mainly boil down to the fact that such a hard-coded rule could have many unintended negative consequences, such as disruptions in important threads like Making a Line For What Content Not to Include, which by their very nature deal with nsfw topics. But I guess if the rule was instead written as a general suggestion to try to keep topics and posts pg13, then it would cause basically no issues, as it would just be putting the status quo in this matter on paper (…or post in this case?).
ahhhh this is starting to feel more and more like a conversation that’s gonna get moved…