The Twitter account vx-underground published screenshots of correspondence, allegedly of the person involved in the GTA VI leak.
The most interesting point is the mention of the game's budget. According to the malefactor, the development costs were over 2 billion dollars, and this is the record-breaking amount for the game's industry.
To better understand the scale of Rockstar's expenses, note that the Polish studio CD Projekt RED spent 317 million dollars on Cyberpunk 2077, and for the creation of Red Dead Redemption 2 it took about 300 million dollars (excluding marketing).
In the screenshots you can also see the information that the development of GTA VI began in 2014, but the full production of the game started in 2019.
That said, the GTA VI release date is so vague that it is impossible to make predictions. Originally the game was expected to be released in 2023-2024, but insider Adrien Perea shared that GTA VI release will not happen before 2025.