Mario Kart 8 Deluxe sells 459,000 copies on launch day in US, fastest-selling Mario Kart in the US.

[b00moscone]

Also some other things to take into account, MK8D also beat MK7/8 in the UK, and in COMG (Japanese pre-order numbers) MK8D beat out MK8 (Though ratios can mean it could go higher or lower), so it's not far-fetched to say that MK8D has done 1m+ FW, if you were doubting it still.