I think what needs to be looked at here is what is the defines cyberpunk from other genres. From what I've gathered on a quick search, it seems to be defined by high-tech advancements; such as cybernetics, ai, and other such, and low-life societal conditions usually associated with dystopia or societal decay. Of the three movies you listed, I've seen two. Astro Boy fits this the best, considering the stark contrast of conditions between the cloud city and the surface. Next Gen is good, but I don't know how well it fits since it seems everyone lives a pretty decent life, at least from what I remember of the film anyway. Have not seen the last one on your list. I personally can't think of any movie that would be considered cyberpunk for kids off the top of my head. But I'm sure it exists somewhere. Even if the story is made more palatable by having the hero win a decisive victory over the big bad corporation (or any bad guy really), it can still be cyberpunk. Just maybe a more optimistic part of the genre.