https://www.gamespot.com/articles/with-fortnite-playground-issues-continuing-epic-re/1100-6460099/

Along with the sandbox-style Playground mode (which currently remains offline while Epic irons out issues that cropped up shortly after it launched), this week's Fortnite: Battle Royale update marked the start of another limited-time event, Final Fight Teams of 12. After receiving fan feedback, the developer has announced it is disabling Final Fight and replacing it with another iteration of the fan-favorite 50v50 mode. [Update: Following earlier issues that prevented its rollout, Epic announced on Twitter that 50v50 mode is now live in Fortnite: Battle Royale. Playground remains unavailable.]

Despite only being available in the game for a couple of days, Epic says it decided to disable Final Fight after listening to the community's feelings on the mode. "We've heard your feedback regarding the Final Fight LTM and we agree that the mode isn't quite in a state where we want it to be," the developer wrote on Reddit. "Due to this, we'll be disabling Final Fight and re-enabling the 50v50 LTM."