These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
HBase's internal use of GSON is now done in a stand alone module named hbase-shaded-gson rather than as a part of the hbase-shaded-miscellaneous module. The relocated fully qualified class names are still the same.
This internal artifact is also set to maintain JDK bytecode compatibility as appropriate for use with branches-1 based releases in addition to the existing use in later release lines.