Earlier quoted context omitted.
> All scientific research on this topic points to the conclusion that standardized test results are the single best predictor of subsequent academic performance. And academic performance is measured how? With standardized tests?
Obviously, yes. This is not circular: it is by no means tautological that people who did well on test X will do well on a completely different test Y that tests different knowledge and skills. The fact fact that it does gives strong evidence to the value of using these tests for admission.
So the question is, how much do these tests actually test skills in the subject matter and how much do they test "meta skills"?