While Red Dead Redemption 2 is releasing on multi platforms. RockStar and Sony are still partnering up to ensure that the Playstation 4 version of Red Dead Redemption 2 is best way to play. Playstation gamers will be getting first dibs on  multiplayer content scattered throughout the vast world of Red Dead Redemption 2. No word yet on what we will be seeing for exclusive content, we will get more updates closer to release.
In addition Red Dead Redemption will now be streaming on the Playstation Now service which is available on the Playstation Now app on many entertainment devices.
Source: PS Blog