"Range-extended vehicles are not hybrids; they are electric."

Yeah... no. It's a hybrid fuel system if its using both a fuel in the turbine as well as the battery pack. When people say electric drive, it's not the same as electric vehicle. The VEHICLE has a hybrid system even if the drivetrain is using only electric power. Similar to if your home uses both electricity for the lights and gas for your water heater, you have two power sources, even if the lighting in your bathroom is electric when you take a shower you're using two power sources. Their range-extended electric drive system is range-extended because it's using a fuel thus is a hybrid vehicle. This isn't complicated.

"Doubtful" is technically correct: range-extended electric vehicles can also be called series hybrids. However, we find that if we call it that, most people assume it still has the diesel piston engine. The difference between a parallel and a series hybrid is lost on most folks. Common usage now is that "hybrid" is taken to mean parallel hybrid like a Prius, and the Volt is not referred to as a hybrid, but as a range-extended EV. So we went with that usage too.