The next major update is mostly the same as described in the last Dev Log, mostly it'll have 3 new features:
Analyze Feature, which is a step-by-step explanation of techniques and methods used to solve a puzzle, similar to Hodoku or Sudoku Explainer
Campaign Feature, which is basically Sudoku lessons, using text and pictures and exercises to help beginners learn Sudoku techniques and methods, and is planned to support Steam Workshop.
Paint Feature, mainly used to express the logic of solving puzzles through images.
After 8 months of development, these new features are halfway done, but they are still far away from completion. So we have to change the expected release date of the Update from end of 2024 to some time in 2025.
In addition, plans for multiplayer features, Sudoku variants (such as Killer Sudoku), which were in the long-term development plan, have been cancelled. Languages except Chinese and English, are going to be removed. The main reason for these changes is to focus development time on single-player features over the next 2 years, which will bring more value to players who only need single-player features. Below are the latest screenshot of the in-game Paint feature (in development and subject to change): 
Other new features are not finished yet, so we do not show screenshots of them for now. I'll go back to work now, see you when the update is ready!