https://www.gamespot.com/articles/season-6-fortnite-update-removes-a-bunch-of-weapon/1100-6462101/

Epic kicked off Season 6 of Fortnite this week with the release of the game's 6.0 update on PS4, Xbox One, PC, Nintendo Switch, and mobile. As expected, the patch made some big changes to the battle royale game, introducing a handful of new weapons and locations to the map on top of an extensive list of cosmetics and rewards that can be unlocked with the Season 6 Battle Pass. However, players may notice that a few popular weapons are no longer available. [Update: It isn't just old weapons--due to a bug (rather than a design decision), the new Shadow Stones have been removed temporarily from Fortnite while Epic works on a fix.]

As part of the 6.0 update, a handful of weapons have been moved to the "vault." This isn't unusual, as Epic periodically removes items from the game in order to further tweak them or make room for new ones, but this time, the developer has vaulted a larger-than-usual cache of weapons. Specifically, Epic has removed the Impulse Grenade, Suppressed Submachine Gun, Light Machine Gun, Bouncer, and the Remote Explosive.