The link points to a product that powers a weighing scale whose power requirements is 100mA @ 5V to 9V so I would say no.
Stepping down DC voltages (Buck conversion) is always easier than stepping up (Boost conversion), using simple switchers anyway.
So technically it is possible, but the cheap switchers you get off eBay are quite rubbish, especially the step up ones, most use fake chips as well making wild claims (95% efficient). A properly designed boost regulator boosting 5V to 7.2V at 500mA and 90% efficiency is not difficult using modern components, but it is difficult finding an off-the-shelf solution.
Note that 500mA @ 7.2V = 3.6W which then equates to 720mA @ 5V assuming it is 100% efficient, which it won't be.
I am not sure about the peak power requirements of the Nikon but for the Canon 6D I measured circa 500mA with LiveView and about 300mA when exposing (at 7.2V). Since there is no flash there aren't any huge gulps charging up the flash capacitors so that helps (as mentioned above).
The other thing about USB hubs is that if it complies correctly with the USB specification it will only supply the higher power (500mA or more) after negotiation (which your wire won't provide), however some/most powered hubs will gladly supply much more power without negotiation. Modern hubs come with "charger ports" to overcome this.
Since I had 12V as well as the powered hub providing 5V, I opted for the 12V down to 7.2V route instead.