"Japan studios comprised
originally of 4 teams."
None of these 4 teams existed when Japan Studio was originated back in 1993, when using other branding name then, as they use other branding ones now.
That studio changed their name, moved from division and merged in or separated the 2nd party publishing/support team from the internal development team even if the team kept there in the same building doing the same: one part internally developing games and the other one publisihing/supporting 2nd party games.
Again everything you said means Japan studio was disbanded and the remnants are within Team Asobi, Polyphony Digital, Bokeh Studio, Gen Design and XDEV.
Team Asobi ARE NOT Japan Studio.
Like saying Treasure are Konami or Platinum games are Capcom.
No, it isn't the same.
Team Asobi is the internal development part of Japan Studio with another name. They rebranded it -as did multiple times before- in this case because they decided to split the 2nd party part and to merge their internal development teams into one of them. So got rebranded to get the name of that one.
Polyphony, Bokeh, Gen Design never had the whole internal development part of Japan Studio, they started with a few members form Japan Studio who branched out/left/were fired.
Same goes with Treasure or Platinum, they were just a few guys, a small portion of the internal development part of Konami or Capcom. Not the whole.
Some extra info: Nicolas Doucet, head of Team Asobi, didn't become studio director in the restructuring of 2021. He became the studio director of Japan Studio in 2019. And appears credited as such in Demon's Souls remake (published in 2020).
About branching out the 2nd party publishing/support team to spinoff from the local team, it isn't something new or that meant that they "disbanded it": they did it to follow what the equivalent teams for EU and NA did before branching out from Liverpool Studio and Sony Santa Monica.
So now the internal development team (Team Asobi, Liverpool or SSM) could focus only on making their own games while also having a lower cost. And these local 2nd party publishing / support team no longer had to report/receive orders/depend on a local internal gamedev team: they got promoted to be their own office.
In fact the Japanese one recently had been expanded to cover not only the 2nd party games developed by Japanese teams, but now also grew to also cover games developed in other Asian teams. And now works closer with the EU and NA offices as being the three parts of a global XDEV team (in the past, they all three 2nd party publishing teams operated independently from each other).
