https://www.gamespot.com/articles/fortnite-update-510-patch-notes-birthday-event-com/1100-6460686/

Fornite's 5.10 update is now live and developer Epic Games has released patch notes detailing all the additions and changes coming to the game's Battle Royale and Save the World modes. The main attraction in the new Fortnite update is the birthday celebration event, during which players will be able to find birthday cakes around the island and earn special cosmetics by completing challenges and quests. You can check out our Fortnite 1st Birthday challenge guide for more on that.

Beyond that, the patch also preps the game for the return of Playground LTM, which will be playable again from July 25. This time, however, it will include team select options and the ability to drive ATK vehicle. Epic has also promised there will be "lots more loot," though it didn't provide any specific examples.