Recently, a former Rockstar Games developer who worked on GTA IV, GTA V, and the Red Dead Redemption franchise gave an interview to Kiwi Talkz. During the conversation, he spoke about the approach to developing Grand Theft Auto.
Rob Carr recalled the mission Three Leaf Clover (or "Trefoil") from GTA IV, during which the protagonist Niko Bellic carries out a robbery with his accomplices.
The mission had a strong influence on the series:
If you look back now, it is easy to see that this is a kind of blueprint for the three-protagonist system in GTA 5. It is only when you look at it now that you realize: "Oh, yeah, this is actually completely obvious." This is the very mission where three storylines converge at one point.
Carr suggests that Grand Theft Auto VI may feature some elements that were experimented with during work on the previous installment of the franchise, but which were never added to the game.
He also expects that gamers will see familiar elements in GTA VI, but they will be expanded:
There will be things in GTA VI that come from GTA V, which you will look at and think: "Eh, well, we could have predicted that. That is really smart."