I analyzed the GTA VI trailer with my game engine eyes. 👀
It's making heavy use of motion blur. There are no reflections of off-screen dynamic objects, which hints towards conventional screen space reflections instead of ray tracing. In the first scene, I could identify an artifact (see white circle) almost certainly coming from temporal anti-aliasing, which confirms the footage has been rendered with real-time methods. (not neccessarily in real time)
