I also RTFA (admittedly, after I posted) but I still think it's pretty obvious to anyone who pays much attention to space development issues (like, you know, readers of Air & Space). For that matter, this isn't really that much of a step change in terms of lunar landers. The author talks about "Developing a reusable cryogenic space vehicle," but the F9 is only half cryogenic, it's kerosene fuel is chilled to very low temps, but it's not the same as LH2 or liquid methane.
We could build a reusable lunar lander here on earth and put it on the moon pretty easily, but it's not much use if we don't also have some ISRU infrastructure to produce fuel up there too. That gets damn expensive at $60M~$200M per launch, but begins to look more feasible at $5M~$10M. That cost savings is the key enabling factor, not the novelty of design.
The 'big deal' about SpaceX's feat is that they soft-landed a booster stage on earth, enabling reusability for the first time in history. We've been soft-landing stuff on the moon for decades.