I doubt all those child start had perfect lives. I think they were lucky they didn't grow up in the toxic social media world where you had to be online 24/7. They wrapped up the last movie just before social media peaked.
Emma Watson or Daniel Radcliffe no doubt didn’t have perfect lives as child stars but they have handled their stardom far better than their peers from the same time
The cost of this kind of exit is going to be always higher than any voluntary termination . Lawyers are not dumb this loophole would have pretty obvious early on, Disney has had decades of experience handling child stars she is hardly the first star or the first one to have problems with her image for Disney.
It just seems like a PR reason, it could perhaps explain until contract termination by Disney not the next ten years after the image she has built.