https://www.polygon.com/2017/10/23/16527268/grand-theft-auto-5-single-player-dlc-story-expansion

Rockstar Games has found success with story-based single-player add-on content for games like Grand Theft Auto 4 and Red Dead Redemption, but the company’s latest release — 2013’s Grand Theft Auto 5 — never got a story expansion.

Rockstar did have something planned in terms of additional single-player content for GTA 5 at one point. “For those ready to jump back into the story of Grand Theft Auto V, we have big plans for substantial additions in 2014 continuing Michael, Franklin and Trevor's action, mayhem and unexpected adventures in Southern San Andreas,” Rockstar said in a post on the Rockstar website in 2013.