Yeah they seemingly already have Japan in the bag, so they now feel confident that they can put off some shipments from coming there to bring more to the west. I guess if those shipments continue to sell well that's not the worst idea.
Just sucks for Japanese people who are still looking for a Switch.
Nintendo dug itself into this position over time, starting with the knee-jerk reaction to the failure of the N64 in Japan, where instead of building on SNES like numbers in America and putting out a console that played to N64's strengths, they put out the GCN, scrapped online plans, sold Rare, tried to win exclusivity with Capcom, etc. This just landed them with a weaker position abroad and still as also-rans in Japan and called for them to try and do something different, hence the Wii. It was successful at home and abroad, but also the sort of console Japan needed in the face of the HD twins and HD development. The thing is that the Wii stagnated in its last years and the Wii U was a muddle-headed successor that failed in all markets, leaving Nintendo with just its portable hardware as a success. Portable hardware that also was lopsidedly relevant in Japan by that point.
Basically Nintendo "won" back Japan from Sony, but it puts them in a tough spot as the Japanese market is shrunken and large Japanese companies are variously divested from it as "chasing the west" increasingly means simultaneously ignoring Japanese preferences and as the mobile scene exploded in Japan attracting what efforts were intended to make money off Japan.
So Nintendo needs to both a) try and maintain (or expand) its Japanese market and b) expand again outside of that market and the two feed into eachother. Namely, getting the support to engage Japan increasingly means providing for Switch/PS4 multiplatform but also making the Switch and Japanese games on the Switch a success abroad. So in a sense b comes before a. But a also comes before b in the sense that Switch's most likely support is from Japanese companies and being a hot product in Japan is going to be a distinguishing feature to make it relevant to those companies, as with the DS and 3DS.
They have the hardware and they're off to a good start in hardware sales and at least in the west the installed base seems quite engaged wrt things like indies. They need to build on this success and get success for Japanese 3rd party software to happen both abroad and at home.
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And expanding relevance in the west also encourages a) indie support and possibly b) western third party support to supplement or possibly supplant what you'd expect they could get out of Japan too, which is another way out of this but is more banking on unknown appeal imo.