Yes, it says that. In its original configuration, I believe it is class D, since that configuration uses a switching FET, and is directly driven by a square wave DDS and driver. There's no way it can be class C, no matter what they say, because it doesn't depend on a tank circuit to develop power, and also because the wave shaping survives the PA stage. As you pointed out, if it was really Class C, that wouldn't be the case. The configuration I am using is driven by a sinusoid, and the switching FET has been replaced with an RF MOSFET that is sufficiently biased that it should be Class A.