Hello FWA
Yes unfortunatly you need to upgrade everything, the reason is pretty simple to explain. When your Backup Exec for Windows Server (BEWS) version was released there was no existence of the HP autolader on the market, this one you got is not only a brand new but also a new generation tape autoloader, that requires support from both Hardware manufacturer and Software Application.
First of all you need to upgrade the main BEWS console and rigth after that you migth need to upgrade all of the options (clients), that's what best practices indicates.