Policy
Age out the locally cached copies of server document versions that are more than n days old
This policy controls when locally cached Office version documents from the server are aged out of the local cache. If you enable this policy setting, Office document versions from the server that have been locally cached for more than n days, will be deleted from the local cache. If you disable or don't configure this policy setting, Office document versions from the server that have been locally cached, will be deleted from the local cache if older than the default of one day.
50b18317572f L_EvictServerVersionsPolicy Registry
Copy registry mappings
HKCU\software\policies\microsoft\office\16.0\common\fileio\evictserverversionspolicyPolicy notes
This policy controls when locally cached Office version documents from the server are aged out of the local cache. If you enable this policy setting, Office document versions from the server that have been locally cached for more than n days, will be deleted from the local cache. If you disable or don't configure this policy setting, Office document versions from the server that have been locally cached, will be deleted from the local cache if older than the default of one day.