Which is pretty much another matter, but thinking that they were the end of all for SIE's Japanese operations is simply foolish.
Same with believing that Team Asobi (previously just a group inside their internal development department) will just keep doing tech demos from now on.
I do blame Sony for this tho, they pretty much tricked everyone into believing that Japan Studio was a thing since the very beginning, when they didn't exist until fucking 2005.
...Which isn't at all what I said. I was commenting on your post, "...nothing of note happened to their Japanese workforce", which A. is unknown at the moment whether Polyphony Digital or Asobi are affected in this layoff count (or any staffers in the XDEV program, for that matter,) but B. is partly the case because there's much less of the Japanese workforce to have something happen to after the closure of Japan Studio.
Japan is still a territory for SIE, sure, (if we have to get into this,) but they did close that office and they laid off many producers who incubate and greenlight games with external development partners under the Japan Studio banner. (Some of that responsibility has since been absorbed by XDEV, but as far as I know Junichi Yoshizawa is no longer there and he produced stuff like Freedom Wars and Patapon with external developers, Teruyuki Toriyama is also gone and he produced Fromsoft's Bloodborne and Deracine.) And then they let go of the internal teams of directors/designers/developers who were working on projects internally. Whether or not Rayspace was a real thing, nothing from the crew is every going to be released because they're not working at Sony anymore.
Asobi survived, thankfully, PD is still active, and XDEV is around to hear new product pitches from Japanese studios (although so far, I believe nothing of Japanese descent has been released or revealed since PS5's launch period outside GT7,) but that era is over and whatever else comes from Japanese developers under the PlayStation publishing label will have been created under a different studio structure than what existed with SCEI / Japan Studio.
(When you say 2005, BTW, are you talking about SCE Worldwide Studios? Japan Studio was not formalized as an independent developer for some of its run, it was just a bunch of people inside the SCEI offices who made games, and most of the games anyone thinks of as "Japan Studio" games were actually developed by partners, but Japan Studio was making games wholly in the office as early as Ape Escape and Legend of Dragoon.)