Don't be alarmed if you're on Xbox One and you see an update going live for Fortnite. This was a small update with nothing really new in it. It was added to the platform to stabalize things, likely to do with some fixes that will help after the Fortnite 13.30 Patch was released yesterday!
Here's the official word from Epic:
We're posting to let you know that we've just released a maintenance patch on Xbox One. This maintenance patch is to address stability.
The 13.30 patch yesterday brought forth the necessary additions to the game that will pave the way for cars to be added. You will no doubt notice that all the vehicles that were scattered around the map have been removed. It looks like cars should be added on Thursday, with the new driveable vehicles taking the place of the stationary ones. This will be a pretty significant change up for things in the game, where almost every vehicle you see will be able to be driven!