Take a simple case
class Node() {
/** @treatAsPrivate */
public void impl_hideme() {}
}
class Button extends Node {
@Override
public void impl_hideme() {}
}
}

Generate the JavaDoc for that.
impl_hideme will not be visible for Node, but it will be there for Button.
Which could have been okay, excepted the javadoc for Button#impl_hideme shows
Overrides:
impl_hideme in class Node

Which is a broken link.
personally I would think that treatAsPrivate should hide for sub classes, but I can see someone who wants to hide the super class and show in the sub classes.