If the Switch Resident Evil game ends up also doing well, do you think Resident Evil IX will be exclusive to the PlayStation ? Especially since from the Capcom leaks that they've been trying to port all their Resident Evil games to the Switch, the Pro might make this a reality and in the future Resident Evil might become a multiplat title for them, same goes for MH World 2, this leads to fewer reasons for Japanese audience to buy a PS5.
Overall there are hundreds of Japanese titles launched each year and only a handful of them are AAA. For AA & indie efforts that are more popular in Asia Switch might be the leading platform. When you aren't guaranteed even 10K sales on the PS5 in Japan for these types of games a PS5 version might not actually make financial sense. After all Resident Evil is a major franchise and it's currently struggling to sell 100K on the PS5 you have to wonder about any studio without the financial capabilities of Square, Capcom & Bandai.