It is a good one, and the authors essentially draw the same conclusions as others who have tried to find some evidence that the "greatest scandal in the history of sports" actually made much (if any) difference in actual performance outcomes. Most of what has come out has not supported the idea that the players actually performed much differently at all while banging on trash cans. I believe there was some evidence that a few players' pitch selection improved a bit; that isn't nothing, but the overall outcomes of the aggregate of team PAs doesn't appear much different compared to "control" settings.
Nobody, of course, is going to hear this (and by "hear this," I mean accept the actual, verifiable data). Any attempt to argue will be drowned out by a chorus of "of course it helps to know what pitch is coming!" and "if it didn't help why did they keep doing it?!?!" and, probably more frequently, "cheaters!!!"
(Note: the first point assumes that they were 100% accurate with the signalling of the pitch that was coming, which they obviously weren't; the second is strange because the report states that they did stop doing it, but then you'll hear about completely made-up "buzzer" talk and the like; the third, although infantile and somewhat meaningless, probably has the most merit of the three.)
There is a legit argument that the intent to benefit by breaking the rules is the issue, regardless of the outcomes. I can buy that. But let's also remember that the Astros haven't been admonished so much for actually cheating as they have for the degree of cheating (i.e., they cheated more than the Red Sox or Yankees did); so is it really about the intent?
If it is about intent, about bad sportsmanship, etc - I agree, the actions are disappointing. If it is about delegitimizing the team's accomplishments - then the critic should actually care about studies like these. But they will not, because they don't fit their preconceived narrative. And that's why this entire notion of "greatest scandal ever" is and always has been absurd and tremendously exaggerated.