Purchase the service! Is this official from D-Link? Complimentary dynDNS service is an incentive to buy D-Link gear and, if you will, part of the contract one expects the company to honor, much like ongoing complementary firmware updates. So, surely D-Link must have a way to reinstate the service with my existing email address. If not, even buying a new router would not make complementary dynDNS service available to me. Weird!.
With respect to Dyn shutting down free DynDNS service, would it be safe to assume that D-Link is among the "longest and loyal Dyn supporters" and as such will continue to receive the service "free for life", - and that this promise should extend to many D-Link's router customers who (indirectly, granted) have long and loyally supported Dyn?.
Wondering . . .