So at the moment the best selling PS5 games during the first 7 months of the console on the market have sold at most 50K physically.
Resident Evil: Village is struggling to sell-out its initial physical shipment on the PS5, Demon Souls and Miles Morales are the biggest Sony published efforts and both games are around 50K sales at best.
For now the only "major" exclusive from a third party for the PS5 is FFVII Remake Integrade everything else is cross-gen Nier Replicant didn't even have a PS5 version. Software sales are going to be worse than X360 during 2005 and 2006 in Japan.
X360 Top Selling Games 2005-2006
Struggling to think of a PS5 game in 2021 that will be able to clear 100K..
If you don't believe the current situation will have profound impact on Japanese third party relationships you are kidding yourself. Combined with a lot of senior people leaving Sony Japan and their market share will continue to decline without serious investment.
Capcoms and Square Enix's flagship titles will still sell millions worldwide. Software in Japan for non Nintendo consoles will be down, thats been a thing for a while. Fyi RE: Village has already shipped 4M copies WW no idea how much they've sold so far if we factor in digital sales including PC.
The smaller niche titles may very well be affected. The rest.. well is just wishful thinking. There's an audience for Japanese games outside Japan y'know :P