operator AND should consider an undefined label as false

Let's say I'm preparing a page where I'm archiving a list of pages labeled by reports and months and years, but we are in october and I have no november label yet. Or, for any reason, a label is not defined yet, but requested in a page by the contentbylabel macro. Wouldn't it be more logical to return nothing if no page has ALL of the labels instead of ignoring undefined labels and returning the result of reports+2007 because november is not found? It seems to me that it's the purpose of a logical operator AND to return false if an assertion fails.

contentbylabel:reports,2007,november|operator=AND