In addition to new features, Oracle Database release can modify, deprecate or desupport features, and introduce upgrade behavior changes for your database
Be aware of the implications of deprecated and desupported:
Deprecated features are features that are no longer being enhanced, but are still supported for the full life of this release of Oracle Database.
Desupported features are features that are no longer supported by fixing bugs related to that feature. Oracle can choose to remove the code required to use the feature. Where indicated, a deprecated feature can be desupported in a future major release.