Pumps are not back in Fortnite as of Season 5. There is no news from Epic about their re-release. The weapon was originally "vaulted" during Chapter 2, Season 3, and it was replaced with the Charge Shotgun in matches.

Will the pump return in Fortnite?

The Pump is back as part of Fortnite Chapter 2 Season 6. Fans have wanted it for a long while, and now it has been confirmed – the Pump is back in Fortnite, as part of the big overhaul that is Fortnite Chapter 2 Season 6.

Will pumps come back in Season 4?

The Pump Shotgun is back in Season 4, returning from the Vault. In its place though, some weapons like the Tactical Shotgun and regular SMG are being vaulted.