Correct, org.eclipse.platform is not a "content" feature (like JDT in the Java package, or CDT in the C/C++ package) that should itself update without being under control of EPP, nor a feature that users typically should uninstall from a package (a requirement that some users have, e.g. to remove parts of Mylyn, just to give an example).
To summarize: The root features are used in EPP to give the users the ability to remove _some_ content from a package, and to enable projects to update _some_ parts of the packages easier than before.
If we learn that the Neon structure of the packages isn't sufficient, or if we see different use cases, we should discuss possible changes for Oxygen early in the release cycle.
Thanks,
Markus
