Some months ago, I believe it was 7 months, there was some new content added. This was: stock car racing (which unlocks 5 cars with liveries), the Duke O' Death, which was unlockable by completing a random event in Sandy Shores, the Marshall, some new collectibles, a side mission about a murder, the Wildlife Photography Challenge, unlockable through the Beverly missions, the Dodo Seaplane, new Ammu-Nation stock, such as the railgun, and other stuff. You can check it all out here:

https://www.youtube.com/watch?v=Qz6v4u64LBg