What an AI Correlation Rule Cannot See
A correlation rule can be tuned. The window can be widened, the join key improved, a source promoted from optional to required. Each of those is a parameter with a defensible setting. What remains after all of it is the residual, meaning the events that would produce a finding if a source existed for them, which is a form of residual risk expressed in detection terms. Naming it is the question an auditor asks after being shown a detection, and the answer is not a tuning exercise.