Cleanup/deprecate methods to identify table from entity name in \CRM_Core_BAO_CustomGroup
5.50 made improvements to the code to identify the table name for a given entity, in the context of which entity and DB table a custom field is extending.
This has rendered the method \CRM_Core_BAO_CustomGroup::getTableNameByEntityName
obsolete.
Calls to getTableNameByEntityName($entityType)
can be replaced with mapTableName($entityName)
I could only find one reference to getTableNameByEntityName, in \Civi\API\Subscriber\DynamicFKAuthorization::getCustomFields
So I suggest we swap that function our, and mark getTableNameByEntityName as deprecated.