Provided Nintendo don't screw it up, Switch 2 should be primed to dominate Japan, as third parties will finally have a system that's powerful enough to handle the vast majority of their titles, but which Japanese gamers actually care about.
Big Japanese games are having to rely on the West for much of their sales at present because of PS/Xbox's poor local performance, while Switch's low power spec rules out most of their more demanding games. Remove that roadblock, and the Japanese software market should see a huge boost.