The reason to keep implementation details out of the docs is that people will rely on those implementation details, and then when their app breaks, they won't e

The reason to keep implementation details out of the docs is that people will rely on those implementation details, and then when their app breaks, they won't even think of looking at the documentation for updated implementation details. After all they probably have the old version all but memorized, and the app may break in a way that isn't obviously related to the implementation that changed.