Letting the community to decide on this is a bad idea because in a modern society the witch hunting mob justice has been replaced by the rule of rational law for a good reason.
Some people will use your chest size or height as the defining factor and others dont even want to see avatars having a cute round face on an adult body because their definition of an adult face is sunken-in cheeks and manly jaw line. It is all vague and up in the air and the most unhinged voices tend to be the loudest and dominant, so there needs to be some assurance that if an avatar is not an intentional representation of a literal child, it should not matter what it may look like to who, ageplay rules should not apply to avatars who do not have clothing or accessories generally associated with children or expressing child like speech and behaviors that are necessary for to fit the textbook definition of ageplay. As it is now, it makes life difficult for everyone involved, people whos avatar some karen deemed "child-like", pressure and headache for sim owners on who to let in, communities being wholesale banned form places, everyone on the edge about it, this schizophrenic zeitgeist is bad for everyone's mental health.
Anime avatars are sometimes mistaken for something they arent by people that do not understand anime. Anime facial features such as a round face and large eyes or more realistic japanese body proportions such as a more realistic height and chest size are mistaken for "child-like" features when there are no such intention.
Also this needs clarification "Note: Merely having a childlike avatar does not violate this policy. It is not our intent to banish childlike avatars in and of themselves."
So merely having an avatar that some misinformed person deems "child-like" does not violate this policy in in terms of adult activity or general terms of this type of avatar simply existing? Does this mean adult activity is allowed?
During the governance meeting "presenting as under 18" was thrown around in regards to avatar appearances, with no clarification given on what does that mean or who decides if what your avatar is "presenting" to be, is it up to the user or an arbitrary third party decision, and is "presenting as someone under 18" mean the same as "child-like" ? or are "child-like" avatars ok but the "presenting" ones not?