Shiv L, you can check the ePO 4.6 installation guide, under the Upgrade McAfee ePO Software on page 31:
One plus with 4.6.4 is that you no longer need dbo rights to the database to update to 4.6.4.
I'm not aware of any changes to the rights required for updating - have you got any more details?
Oops, my bad, CREATE_DATABASE permissions no longer required to upgrade:
"Issue — CREATE DATABASE permissions are required to perform an ePolicy Orchestrator patch or upgrade. (Reference:
Resolution — CREATE DATABASE permissions are not required to perform an ePolicy Orchestrator patch or upgrade.
Note CREATE DATABASE permissions are still required to perform a fresh installation of ePolicy Orchestrator software."