A major update of this release is the integration of the Zest 2.0 development branch. See the wiki for more details.
Apart from that this release focused mostly on code modernization, bug fixing, and performance improvements.
A full list on all issues and pull request handled in this release can be found here: https://github.com/eclipse/gef-classic/milestone/7
The update site for this release can be found at: https://download.eclipse.org/tools/gef/classic/release/3.22.0/