No, what Nintendo confirmed was, that they _shipped_ (sold to retailers) 3 million units by the end of december 2012. Only a part of that is sold through to the consumer (that's what vgchartz is trying to track).
Nintendo formerly had a shipping target of 5.5 million by the end of march, but in the same report in which they announced the 3 million shipped they lowered their own shipping target to 4 million WiiUs by the end of march, so reaching the initial 5.5 milllion doesn't seem possible.