Another user on Reddit, gfk53, posted a leak about the upcoming GTA 6.

He states that he was shared this information by an inside source and was asked not to spread it. But he did. And here are the key moments:

• The game takes place in North America and South America. Its current code name is "Project Americas".
• GTA 6 will be released for the next generation consoles (PS5, etc.).
• The map includes 3-4 major cities: Vice City / Everglades, Havana (Cuba) and somewhere in Panama / Brazil / Colombia (these parts of the map are still under development).
• Vice City will serve as the major focus but we may not start out there.
• All the cities/islands outside the US will be named by their real names.
• It is unknown how many times bigger the GTA 6 map will be compared to GTA 5, but it is very spread out. So it will "feel" bigger (apparently, due to a number of locations).
• The cities will have depth as opposed to scale. Meaning more enterable buildings and interactability.
• Each city will be separated by large distances of water. The player will likely be able to skip the travel (like the taxi ride in GTA 5), but on your own it might take you 10-15 minutes to fly to each city across the map (impressive, isn't it?).
• GTA 6 is in very early stages of development, and not much is known about the story (it's been almost 7 years since GTA 5, Rockstar, time to hurry).
• The time period spans over multiple decades (70s, late 80s and present day).
• A drug smuggler named Kacey is an important part of the story.
• Time progresses through the game as you play. So each "chapter" will be set in the 70s, or 80s, and as you play through the mission. Songs will change, buildings will become closed, cars and characters will decay with time. This was concluded by the insider person because cars that predate 2000 are being designed in multiple stages to mimic the progression of time. And there's a lot of vehicles being made that predate present day. At the moment, almost 70% are before 2020. 30% are present day.
• Weather conditions can now cause hurricanes (category 4-5).
• There is a huge prison in the game, possibly a variant of Guantanamo Bay. It may definitely play a major role in the story. Maybe break out missions.
• Drones are being modeled in the game.

There is also some information about Bully 2.

• Bully 2 is the next Rockstar project. The protagonist is a freshman Jimmy Hopkins, but this time it's in a university next to a large fictional city.
• The map will be as big as GTA 5. However, the city will have a grittier tone.
• There will be three equally sized environments (university, city and woods).
• The game will also feature cars.

Again, everything sounds plausible. Many things are the same as in the leak from JackOLantern1982. True or not, we'll see it soon. The Reddit user who posted it (gfk53) was deleted (it's interesting why?). But the post somehow managed to survive. Here is a screenshot: