Verizon even says so on their website. It must be a glitch on Apple's end.it was all over the tech sites a couple of weeks ago that at&5 was going to charge upgrade fees, even for NEXT customers.
"The $40 upgrade fee applies any time you purchase a new device at a discount, with a contract extension, to replace an old device. This fee is in addition to the cost of the new device and applicable taxes. The upgrade fee does not apply when a new device is purchased at the retail price."
http://www.verizonwireless.com/support/upgrade-fee-faqs/