Digimon Survive was originally slated for release in 2019, but during an Anime Expo panel, Bandai Namco confirmed that the game has been pushed back to 2020. We didn't really get an explanation for the delay at that time, but now we have a statement from producer Habumon that gives some insight.
“Regarding Survive, the planned release date has been changed to 2020 because of a reorganization of our game development structure. Sorry to keep you waiting. Once again, I feel deeply the hardships of game development… We will continue to develop the game in order to make it a good product, so please look forward to it.”