Indeed, even the most optimistic rumors are saying that the game isn’t coming out until 2018, and by then a lot could have changed in the plans that Rockstar have for the title. Even if some of the things listed above are true at the moment, they might turn out to be outdated by the time the game comes out.
Plus, technology is going to advance a lot until then, and people are going to have different expectations for a game as well. We don’t know what else might arrive to the market by the time “GTA 6” is ready to roll out, but Rockstar are going to have to put a lot of effort into their work to avoid falling behind the trends.
That’s actually one of the biggest issues with long development cycles like the ones Rockstar typically have for their games. By the time the studio is ready to show their work to the world, the situation is different.
And what looks like amazing next-gen graphics now could be laughed at two years from now, but it’s not very easy to design a game in a way that accounts for that and leaves the door open for further improvements to its graphics. Because of this, there will likely be a lot of planning before the game is actually ready for a release and is even talked about publicly.
Are they planning the game already? Please, they start planning the game before the previous one is even released.