McK's case interview is just as game-able as HackerRank style interviews. There are entire consulting clubs at many colleges that teach this exact interview style. It's true that it's harder (but not impossible) to use AI to help, but calling it an IQ-like test is true only as much as any other technical interview.

That being said, McK did create an entire game that they claim can't be studied for ahead of time. If the intention is to test true problem solving skills, then maybe that's roughly equivalent to a systems interview, which is hard(er) to cheat .