They may have announced the sequel, but they didn’t announce any further details, as we still don’t know which platform they will release this Science Adventures series game in.
However, much like the Robotics;Notes sequel, they didn’t announce much details, though we do know they’re adding some new elements for the game.
They also revealed Steins;Gate Elite, which is a major update for the Steins;Gate game.
This includes Robotics;Notes DaSH, which is the “true sequel” to their Robotics;Notes games.