The old standard doclet is already marked @Deprecated, and superseded by a replacement as part of JEP 221.
http://openjdk.java.net/jeps/221

We are retaining the standard doclet for JDK 9 because the class name has been publicly documented, and because we have reason to believe that some folk have been relying on the implementation of the standard doclet to create customized doclets.

However, the old standard doclet is not being maintained and folk using it should convert to using the new standard doclet. As such, the old standard doclet should be marked @Deprecated(forRemoval=true) with the intent to remove it and all the related internal implementation classes in the next major release.