This page provides more detailed information about the automatic zone map creation and maintenance.
Oracle Database 21c allows you to enable automatic creation and maintenance of basic zone maps for both partitioned and non-partitioned tables by using a new package and procedure,
DBMS_AUTO_ZONEMAP.CONFIGURE. Automatic zone map creation is turned off by default. Enabling automatic zone map creation does not require any DBA intervention for both the creation of the zone maps and their maintenance. Nevertheless, zone maps can still be created manually. Automatic is for Cloud autonomous database and Exadata only.
This functionality is not available for join zone maps, IOTs (Oracle Index-organized Tables ), external tables, or temporary tables.