It's far from guaranteed, but since you asked "Can it...?" - Why not? Perfectly possible.
It's basically guaranteed. Splatoon shipment was at 2.42mil end of Sept. Bundle sold 140k in Nov us only. It needs to do under 440k by end of year. That will be achieved alone in Japan.
Sold through should definitely be very close to 3mil if not above it by end of year.
US about 900k excluding dec
Japan 1.1mil now