The README that corresponds to this release is:
https://github.com/mozilla/policy-templates/blob/e529c897e63902ab79619e28519bd897f9494d06/README.md
This release updates the following policies:
DisplayMenuBar - Added additional options for always on or always off.
EnableTrackingProtection - Exceptions added
It adds the following preferences to the Preferences policy.
dom.xmldocument.load.enabled (Firefox ESR 68 only)
dom.xmldocument.async.enabled (Firefox ESR 68 only)
It removes the following preferences from the Preferences policy.
browser.cache.disk.parent_directory (Wasn't working correctly)