Just looked it up, Switch already beat the GameCube in Japan.
N64, Saturn and Vita are up next and will be overtaken soon. (500-800k ahead so not much)
PS4 is a bit further but Switch will also get there pretty soon. I think Switch could overtake the PS3 before the PS4.
Much of this success can be attributed to Splatoon 2. It has 52% attach rate in Japan. Good move by Nintendo.