If your company hardening policies require to show the welcome banner on each CVM each time a user logs in, you can disable it, make the necessary changes per our Security Guide (https://portal.nutanix.com/#/page/docs/details?targetId=Nutanix-Security-Guide-v5_16:Nutanix-Security-Guide-v5_16) and then reenable it.
The following KB 8534 has the complete procedure and the commands needed to apply the banner changes in your environment.