The big problem with publishing games in Japan is that a Japanese subsidiary or independent publisher in Japan is necessary to get your game released there. Why? Because the Japanese rating organization CERO demands a Japanese office. And the console manufacturers demand a CERO rating for each game that releases on their system (probably by law, I haven't looked that up, but that seems pretty standard to me).
So to get your game onto the Japanese Nintendo eShop or PSN hasn't become any easier. But because the Switch is now region-free, Japanese gamers can get their games from the US/EU eShops. As long as developers have a Japanese language option is their game (available in US/EU, but not in Japan), Japanese gamers can still play their games in Japanese while developers avoid that CERO hurdle. The best thing is still publication on the Japanese eShop tho imo.