The way GTA Online DLCs keep leaking, we might not even need official announcements anymore for them. The game files of the recently released Lowriders: Custom Classics DLC also contained data pertaining to future updates for the game. It wasn't long before these files were discovered and loaded up to see what info could be revealed.

The Custom Classics DLC was also leaked ahead of schedule, revealing one of the new cars that was added to Benny's, as well as another one that is still on its way. The Custom Classics trailer ended with a teaser saying that more lowriders were coming soon — true enough, the files of Custom Classics contain more cars than just the three that were added.
Some of the new assets and prompts that were discovered in the files all follow the same theme: sports. American "football" (handegg?) specifically. The assets make it seem like the new update will contain a new Adversary Mode which is styled after football, using the titular prop as a "package".