Tabata left his position as studio head of Square Enix's Luminous Production on October 31, 2018 in order to establish JP Games He made the announcement on Facebook (via Gematsu)
From Gematsu:
Hajime Tabata, who directed Final Fantasy XV and left his position as studio head of Square Enix's Luminous Production on October 31, has announced the establishment of a new company called[...]