Policy
Keep the last AutoSaved versions of files for the next session
This policy setting determines whether PowerPoint keeps the last AutoSaved version of a file if a user closes a file without saving it. (Note: AutoSave applies only when AutoRecover is enabled.) If you enable or do not configure this policy setting, PowerPoint keeps the last AutoSaved version of the file and makes it available to the user the next time the file is opened if the user closes a file without saving it. If you disable this policy setting, PowerPoint does not keep the last AutoSaved version of the file if the user closes a file without saving it.
02434e8b5fba L_KeepLastAutoSavedVersions Registry
Copy registry mappings
HKCU\software\policies\microsoft\office\16.0\powerpoint\options\keepunsavedchanges (enabled) = 1
HKCU\software\policies\microsoft\office\16.0\powerpoint\options\keepunsavedchanges (disabled) = 0 Policy notes
This policy setting determines whether PowerPoint keeps the last AutoSaved version of a file if a user closes a file without saving it. (Note: AutoSave applies only when AutoRecover is enabled.) If you enable or do not configure this policy setting, PowerPoint keeps the last AutoSaved version of the file and makes it available to the user the next time the file is opened if the user closes a file without saving it. If you disable this policy setting, PowerPoint does not keep the last AutoSaved version of the file if the user closes a file without saving it.