On the subject in the title: Managing an unplanned gap in supply — what changed since Working notes rather than a conclusion.
A coverage question with the paperwork detail included, since that is what determines the answer.
Denial received, with a stated reason. My reading of the reason is that it tells me exactly what to submit next, which is the useful thing about a well-written denial.
Before I spend a week on it: is my reading of the stated criterion correct, and is there a documented precedent for this specific ground?