The Document Generation Services 2015.2.0.4347 release has been updated to include the Expere Engine version 2015.2.0.3237. No user action is required.
The Document Generation Services 2015.2.3 release has been updated to include the Expere Engine version 2015.2.3. No user action is required.
Release notes for the Expere Engine and the Expere Authoring tools are documented in the Expere Release Notes