License reactivation during vCMP host upgradation

Is it still mandatory to re-activate the license if am ok from above perspective? Always best practice is reactivate license before upgrade

While reactivating the license, will I require the original license key for the device to re-license again. Or will it appear automatically when I try to re-license?

If you have valid support contact from F5 vendor, just go ahead and reactivate license with existing license key (No need to update it will show automatically).

Please let me know any more information is required