Despite this, Rockstar Games hasn't added to the single-player experience in any significant way, and has rather focused on improving and expanding Red Dead Online, the online multiplayer experience of RDR2 that's free to all owners of the game.
Okay, Rockstar Games didn't actually confirm this, but when asked about the future of the game and the possibility of single-player DLC, Rockstar North's Tarek Hamad simply emphasized that the team is focused on Red Dead Online.
As you may know, this lines up with what Rockstar Games has said in the past and what Rockstar Games has done with GTA 5, which received no single-player DLC, but rather has lived beyond its initial release via GTA Online