I don't wanna start this, but you should keep in mind that, the last Splatoon update is from September, and since that, it sold A LOT.
Is easy over 4 million, Nintendo will annunce this soon i can assure you, and BloodBorne will never sell that much... Also 4m just this year. This game has insane legs, that's a important fact for it's succes.
Don't get me wrong. BloodBorne is a succes. 2m is good, and I can see ~3m LT, which is awesome for a similar Souls game...
But Splatoon succes is way bigger than BloodBorne. I don't know if you guys know, but Splatoon has almost for sure outsold Halo 5...