And before the box could actually tell Nielson that information, which is EXTREMELY recently, Nielson obtained this information by sending out surveys to random households to ask them to write down what they were watching and who they were watching it with-- ages, gender, etc.
My suspicion is that they're covering it up for two reasons. Obviously, one of them is to fuck the creators. It would simply be out of character for Netflix to NOT factor that in.
But the other, I suspect, is that there's a shape to the data that isn't what they want to display. I don't know what that shape is, but the history of television is full of shows that were cancelled because they had the wrong audience. (Usually, women.) Because they don't just have audience numbers. They have ages, genders, and any other demographic data that you have provided them or they have been able to get through infernal internet methodology.