While a lot of us correctly assumed this before, this is the first official confirmation of it being the case.
It's worth noting that XDEV is not a single entity, but rather a global group encompassing three different studio departments across USA (previously known as San Mateo Studio), United Kingdom and Japan.
XDEV Japan is situated inside of Sony Interactive Entertainment Inc. (the Japanese branch operating since 1993), and it was originally established in April 2020 as part of the WWS Japan Studio division, before moving on to the current Japanese branch of PlayStation Studios a year later, when it started to expand its production business in other parts of Asia, including South Korea (Stellar Blade) and China (Lost Soul Aside, Convallaria); with all this information corroborated by both Hermen Hulst and several job listings.
*Credit Nial on gaf