That's a bit extreme I think. In all fairness, consider what would happen if a customer archived a project, and then, let's say after 90 days, it was removed from the system. Then the customer decides 6 months later that they need access to those files that they forgot or neglected to archive on their local server. Whoops... they're gone.
Trust me - there are customers out there that would immediately be threatening lawsuits over that, no matter how many disclaimers and warnings they've gotten from Autodesk that their archived project was about to be deleted. How many emails from Autodesk go ignored?
When a project is archived, it can not be viewed by anyone that's not an account admin. It cannot be restored unless by an account admin. For all intents and purposes, it IS gone. Until it's needed for some reason.
Since there's no limit to how much storage is used, I don't see the problem. If you're worried about someone at Autodesk accessing your files, then you probably shouldn't be using ACC at all - or at the very least, download the files from your project and delete them when you are ready to kill it off.