It was pre-emptive PR, so:
"We're going to lose NPD....again. But we want you to think we're doing well"
And, apparently, it's done it's job. People are actually thinking that XBone really is close to 10 million in sales, despite the launch 3M sales WW + all 2014 NPDs + weak Europe + meh China + DOA in Japan show that it's not near there yet.
No, that wouldn't make any sense. "Shortly we will have shipped 10 million" clearly means they're at 9.999M shipped and there's no way MS didn't rev up shipments in lieu of price cuts, bundles, black friday and the holiday season in general, and then use that shipment figure (probably meant for the entirety of the holiday season) to make everything look great.
No different than when Sony announced 7 million sold in April, so MS turned around and announced 5 million shipped, literally the next day (and these numbers were after the fallout of revving up shipments for Titanfall). PR tactics to make it seem like they're "not far behind", when they really are