You say oracle.jdbc.driver is desupported, yet the package is still in the jar files?
Customer use of the package is desupported. We did not remove the package or the classes it contains. This package is the core implementation code for the driver. We could have renamed the package but did not because it would have been a lot of work for not much gain. What we did do is change the visibility of the classes and methods in the package. Most of the classes are now default (package) visible instead of public visible. Many of the internal implementation methods used to be public visible. Most are now more restricted. These are the changes that would cause source to give compile errors or compiled code to throw runtime errors.