Yeah, seems like it was a new support guy who didn't fully understand what an unlocked bootloader meant. In the past, VZW has stated they won't prevent you from activating your own compatible devices as long as you pay for the appropriate plan and it doesn't represent a security risk. That may be changing, but it was pretty much a guarantee that those with rooted phones, custom ROMs, kernels, etc had nothing to worry about.
Even with their less friendly recent policies, I still wouldn't expect VZW to try to prevent this, or even be overly active in trying to lock down devices they sell if the manufacturer wants it open based on consumer feedback. It would create a pretty negative image and push customers away, not to mention the very people they would be fighting against (rooters, hackers, modders, etc) would ALWAYS find a way around it, and may grow bitter enough to cause them harm.
Look at how successful Sony has been recently with such efforts, for example...