There are lot many changes from 5.x to 7.x versions, I believe you are testing agent manually like from designer studio. Probably an operator ID instance will be created to keep a track of the user who ran the agent.
From the designer studio I remote traced the agent requestor and found that OperatorID page is there without any data other than pxObjClass. Previously in 5.x version for agent requestor OperatorID page was not present at all. So wanted to know why OperatorID page is now exists without the details. Is there any specific reason to create blank OperatorID page?
This question is coming from the below issue:
In 5.x version some condition are written - if OperatorID page doesn't exist with class consider as batch requestor otherwise other requestor type (browser). If OperatorID page exists In the next condition do some check from OperatorID page assuming it is a browser requestor.
Now after upgrade to 7.x since OperatorID page is existing all these conditions are failing. May be the conditions can be reconstructed but just curious to know the need to keeping blank OperatorID page.
I did a test at my local 7.1.8 setup, I ran an agent activity with tracer on and saved the tracer xml file.
When I reveiwed tracer xml to search for 'Data-Admin-Operator-ID' and found that 'Data-Admin-Operator-ID' is mapped with current pxObjClass for pyLabel as 'Operator ID' like you said and later pzIndexOwnerKey is set as 'Data-Admin-Operator-ID <operator_id>'.
From this I understand that 'Data-Admin-Operator-ID' instance is used for indexing the rowdata returned for each page.