I can see whats wrong with the left side, but the right side doesnt make them predators

I mean, most cartoons have adult jokes and/or imagery to them that flies over the heads of kids, such as this:

Nothing new there, and the one shown in Mao Mao here is not any more graphic than Dragon Ball Z's chapters where they get eaten by Buu and they are shown inside of him for several episodes.

I can trace Julia's case and I se the sources and point at hand, but the other 2..? "They made porn before" is hardly anything alarming or worth taking seriously. Anime often gets the same too. JoJo has artists that drew egg-related fetishes before and Dinosaur King's creator is also Boku no Pico's creator. Big whoop, honestly.