Re: "If an adolescent sees a bunch of people comfortable in their bodies..."
I am going to make a sweeping statement but one I feel is probably justified - no one doing this is trying to "display their genitals to children".
I suppose the Surma people of Ethiopia or the Koma people of Nigeria should have their children taken away by us responsible folk forthwith - they are displaying their genitals to children don't you know!
Yes, that's a little facetious but my point is that genitals are not "bad" and children seeing genitals is not, objectively, "bad" either. Hell - children often are washed together; at least we were when we were young.
How young are these "children" you are letting on the Internet unsupervised, anyway? If parents are supervising their children and talking to them - LIKE THEY ARE SUPPOSED TO - then the conversation can be had about nudity and body image in a non-sexual context. If they aren't supervising them then I assure you that they will see nakedness in far less wholesome a context before long.