Mmm yes and no - officially these questions are probably not a perfect reflection of what's on the exam. For one thing, the reference material is strictly limited to publicly available journal abstracts (for a variety of reasons - cost and sheer volume of information mostly) and exam question writers are probably not just deriving questions from abstracts alone. On the other hand, if the abstracts contain good, clinically-relevant, or important concepts related to the study - that info might appear on the exam and the questions generated from this information may be a reasonable simulcrum of what you will encounter.
The goal is to give people a means of reviewing what they know (or more importantly what they don't) in a way that simply highlighting journal articles and re-reading things can't achieve. And to do so conveniently (this site is designed with a mobile-first philosophy).