1) The products should not have a built-in time-bomb that causes them to stop working after only a few years.
2) Dell should have informed us of this issue by email. Instead they left a very "phishing" like voicemail on a manager's phone. (Not the phone of the registered point-of-contract for the cluster.) Perhaps this was done to avoid leaving evidence of #1 above?
3) I spent over an hour on hold when I returned the call, and was then disconnected. After trying again (to an extension other than the one given in the message), I reached somebody who confirmed the issue. I spent another four hours on the phone resolving it.
4) Shortly after all of the above, I discovered a new issue that severely impacted the cluster. The n3048 switch would no longer auto-negotiate a 100Mbps Ethernet link. Our network watchdog device (iBoot) was continuously cycling the power on our Internet Ingress (ONT+ASA).
5) I spent even more time troubleshooting and resolving this issue (by locking the iBoot port to 100Mbps instead of leaving it on Auto).
6) I did not waste any more of my time by reporting this issue. The technician I worked with to upgrade these switches assured me that the firmware releases we used were "stable".