Where did you read that it's because Uncharted 4 has been delayed?
The drop is more because of Disappointing CES2016 Sony conference.
PS4 - over 100 millions let's say 120m
Xbox One - 70m
Wii U - 25m
Vita - 15m if it will not get Final Fantasy Kingdoms Heart and Monster Hunter 20m otherwise
3DS - 80m