The story
Refers to Grand Theft Auto VI (GTA 6), an upcoming video game whose preliminary work began in 2014 and principal development started in 2018. The phrase was popularized in 2023 after sporadic usage since 2020, and the game's first trailer released on December 4, 2023, after which it remained in common usage. It indicates incredulity that an unlikely event happened sooner than GTA 6 got released. It turned into a big meme format around 2019–2022, with images, videos, and captions poking fun at Rockstar Games for delaying the announcement.
Etymology from Wiktionary, CC BY-SA 4.0.