It's highly likely that the sound effects in GTA 6 will be more realistic than in previous installments. With advances in sound technology and the hardware capabilities of current and next-generation consoles, developers can create more immersive audio experiences. The sound effects in GTA 5 were already highly detailed and realistic, and Rockstar Games is known for its attention to detail, so it's reasonable to assume that they will continue to push the boundaries of sound design in GTA 6. Additionally, with the potential inclusion of new settings and vehicles, there will likely be a need for new and unique sound effects to match.