https://www.gamespot.com/articles/fortnites-next-limited-time-mode-just-wants-you-to/1100-6462204/

Fortnite: Battle Royale has another limited-time mode incoming, and this one just wants you to shut up and dance. Disco Domination takes one of the game's most enduring and meme-worthy features and builds a whole toe-tapping game mode around it, having you defend your fellow party-goers as they dance the night away.

An in-game tease gave the name of the upcoming mode and says players will capture and defend dance floors using emotes to score points. An image shows a wild dance party around a disco ball; similar dance floors were previously found in-game as part of a challenge, so this may work similarly. In the meantime, you can continue checking out the current limited-time mode, Soaring 50s.