https://www.gamespot.com/articles/fortnite-season-4-battle-royale-update-vaults-anot/1100-6458636/

Fortnite's Season 4 update has arrived on PS4, Xbox One, PC, and mobile, and it makes some big changes, particularly to Battle Royale. On top of introducing a slate of new skins and rewards to collect, along with comet-induced changes to the map, Epic has removed another weapon from the game for the foreseeable future.

In the patch notes for Fortnite's v4.0 update, Epic revealed that it has taken the crossbow out of rotation, meaning players will no longer be able to find it as loot during matches. The crossbow was first introduced to Battle Royale back in February as part of Fortnite's 2.4.2 update, but now it joins a small handful of weapons in the Vault, effectively removing it entirely from the game.