Origin. In the early 2020s "GTA 6" kept landing on Twitter's trending list, mostly because of rumors. On 19 November 2020 a user posted a clown GIF captioned "Me seeing GTA 6 trending and thinking it's gonna be a release date"; it got about 6,000 likes, and Know Your Meme lists it on its GTA VI page.
How people use it. As a reaction to every false alarm: a clown, a disappointed face, a long sigh. When roughly 90 clips of an unfinished build leaked in September 2022, the joke turned around: "Rockstar finding out GTA 6 is trending for a real reason this time" got about 92,000 likes.
Example. A cartoon character putting on clown makeup step by step while refreshing the trending tab.