Japan is C tier for Sony now.
Europe and NA is where they want to focus and even if they keep MH, DQ and FF going forward, is going to be really hard to sell PS5 when NSW is hot and the launch price is going to be higher than PS4.
Pretty sure all major publishers are ready to support PS5 and not NSW for their AAA games.
Yup.
The bigger threat to Sony is the fact that a bunch of Japanese games are looking at Xbox now. This generation Japan hasn't really been a region about selling hardware, it's about leveraging the exclusive content it provided PlayStation worldwide.
Sony doesn't have to care about how much the PS5 sells in Japan, or whether Switch is selling a lot better, because PlayStation already has third party support locked up. PS4 selling a million or two more units in Japan doesn't really change anything for them.