This is the way Aruba handles the transfer from ClearPass legacy license to new licence during upgrade. The former "Policy Manager" license is converted to a platform activation license. The "Policy Manager" is also converted to 1000 Access, 100 OnGuard and 100 Onboard as Evaluation for 180 days.
You are able to convert the registered legacy license on "asp.arubanetworks.com". If failed, then Aruba TAC support can assist in converting legacy licenses to new license.
However, before an upgrade use the SSH/Console and type "show licences". Copy the licenses to a text file. I have notice that a ClearPass with a valid license for Access is removed when the ClearPass is added to a cluster as a new subscriber. I have seen it in version v6.8. From this point the text file is your backup for re-adding the license.
The Subscription ID is replaced with the login for your HPE Passport Login.
When you have the converted new licenses for Access, OnGuard (if purchased) and Onboard (if purchased), you can update the 180 days Evaluation licences doing this:
Administration -> Server Manager -> Licensing
Select "Applications"
Click on "Evaluation"
A new Window pops up and here you can enter the permanent license.