I feel that having a company release device packs to stay up to date with new products to be monitored shouldn't require a complete system upgrade. New products are released and updated, and any NMS with a decent lifecycle should be able to take this into account.
I recall having to model Cisco ACS 5.8, but not being able to monitor it correctly even though it appeared under Device Certification. Through CA support I later found out that they certified a much older version of ACS, and not being able to have a fix for this other than to wait until a new version of Spectrum would be released which supports the changes made in ACS. I've had similar problems with Juniper routers (SRXes) which were already marketed by the time the latest Spectrum version came out.
A complete system upgrade in order to keep up with changes in my infrastructure is far from ideal, my clients have even gone so far as to express that it's unacceptable.
CA wouldn't be the first to create periodic device packs. Cisco UCM for example provides device packs to support new models and/or new firmwares without having to go through a complete system upgrade. The same goes for McAfee ePo and other popular solutions I've worked with.