Boyer-Kassem et al. argue their result rules out any order-effect-based account of the conjunction fallacy, quantum or classical

Two of Boyer-Kassem, Duchêne & Guerci's (2016, arXiv:1606.03430) seven experimental tasks (the "K." and "Mr. F." scenarios) show a measurable conjunction fallacy with no significant question-order effect at all. Since quantum-like models cannot, by their own mathematical structure, produce a conjunction fallacy without producing an order effect as a byproduct, this pair of results is read by the authors as refuting more than the quantum-specific machinery (claim-boyer-kassem-refutation-rejects-non-degenerate-and-degenerate-models): it refutes the entire strategy of explaining the conjunction fallacy through order-dependence — quantum or otherwise. "Not only are we rejecting the original modeling strategy exploited by the quantum-like literature... but we are also preventing its adoption for any other alternative theory (Bayesian, heuristics...)."

This is the strongest evidence in the paper against reading the result as a narrow, quantum-specific scope limit — the authors themselves generalize past their own program's boundary. It's a distinct move from the field's other "rival formalism" rescues that keep the same target data and swap the machinery, such as the logic-programming account of conditional-reasoning fallacies: here the paper argues the entire class of order-effect explanations, not just one member of it, is unavailable for this particular anomaly. It leaves untouched the order-effect successes documented elsewhere in the vault (claim-question-order-effects-follow-quantum-qq-equality), since those rest on real survey order-effect data, not conjunction-fallacy judgments.

Whether this reach — "fatal to order-effect explanations of the conjunction fallacy specifically" vs. "fatal to quantum cognition broadly" — is itself settled is the open thread at question-quantum-cognition-conjunction-fallacy-fatal-or-scope-limit.