https://www.gamespot.com/articles/fortnite-playground-mode-is-live-heres-what-new-an/1100-6460711/

Fortnite's Playground mode has returned to Battle Royale. The limited-time mode is now live in-game across PS4, Xbox One, PC, Nintendo Switch, and mobile. As promised, a variety of changes have been made, and developer Epic Games has detailed everything that's new since we last saw it.

There are lots and lots of changes, one of which is that players can now switch teams mid-game. The idea is that you can swap sides to work together with friends on strategies and then switch to hone your fighting skills. Voice chat is on for all teams, but Epic plans to add "more customisation" options in the future.