It was originally supposed to release this winter.
Couple of sources:
Gameplay footage from TGS last month:
Couple of sources:
- http://ryokutya2089.com/archives/14542
- http://www.japanesenintendo.com/post/178913378844
- https://gematsu.com/2018/10/yo-kai-watch-4-delayed-to-spring-2019-in-japan
Gameplay footage from TGS last month: