Bloodborne and Demon's Souls are made by From Software. Sure Japan Studio helped, just like Santa Monica helped Thatgamecompany make Journey and helped Ready At Dawn make The Order 1886. But Santa Monica didn't make those games. Japan Studio didn't make Bloodborne, Demon's Souls, the remakes of Shadow and DS by Bluepoint, or Everybody's Golf. They just helped external teams, same as how Sony's XDev are helping Housemarque make Returnal, etc. Its support.
Japan Studio's own PS4 games are Knack, Knack 2, Last Guardian, Gravity Rush 2, Playroom, Playroom VR, Astro Bot Rescue Mission, and some ports and remasters.
That's why they're now just focusing on Team Asobi. Same thing happened to San Diego Studio back in 2016 or so, when they used to have a bunch of devs helping smaller teams make games (Guns Up, Drawn to Death, Killstrain, etc). They all got laid off and the studio was cut down to just the MLB team.