Actually LBP3 released on PS3 too. I think combined they did around 100k. Also, the bundle doesn't release until next week. Quite a few people are no doubt waiting for it.
Plus, it was a very crowded week with at 3-4 other AAA games releasing on PS4
LBP3 will have good legs to 2m+ total sales on PS4 alone.
The One and Only