rodea_sky_soldier on 29 December 2017
Famitsu told on Twitter that switch was at 3.3 million on Japan, by december's 24th, and it equals to 25% of the world wide. So, was at ~13.2 on dec 24th. That 15 million is possible.
ALSO, I made a question on the thread's title and I'm not afirm anything. Thank you very much.