If the market for home consoles in Japan is 22 million and Wii U has sold 1.3 million units then Wii U has "tied up" only 5% of the market during more than 1 year (2 holiday seasons). Also in terms of software market Wii + PS3 sold over 133 million game units. Wii U is at 2.9 million units - only 2.1% of the software market. There is still lots of market to be had by the PS4.
People who would have bought in November are likely to still buy it in Feb. Those sales from Nov to Feb aren't 100% lost.
Long term the availability of popular titles will be a much more important factor than launching a few months early. Titles like Killzone and the current multiplats on PS4 aren't popular in Japan. Take a look http://www.vgchartz.com/game/33543/killzone-3/. Same goes for the other PS4 day 1 titles. The current titles are statistically insignificant in Japan.
In February there will be 3 or 4 titles that have some popularity in Japan. In March there's MGS5: Ground Zeroes. That is what matters.
