On the AI side of the fence the approach has been "let's see just how far Reinforcement Learning can take us, and then start making up stories (hypothesis) about what the secret ingredients are that are missing." On the neuroscience side of things my sense is that that's not a question that can be empirically answered any time soon. This experiment was interesting because they new what they were looking for going in. "What algo are these cells running?" is a hard question, "are these cells' firing activities consistent with this given algo is comparatively easy. Inference vs hypothesis testing.