https://www.pcgamer.com/pubg-announces-periodically-changing-custom-game-event-mode-flare-guns-for-incoming-update/

PlayerUnknown's Battlegrounds is getting an Event Mode, which developer PUBG Corp describes as "a periodically changing preset Custom Game where we will be trying new things and experimenting with different game parameters." It sounds a bit like Fortnite's themed, limited-time offerings. 

But before we talk about that, let's talk about flare guns. "We would like to reveal one of the features that will be included in our next iteration," so reads this Steam Community update post ahead of the following image: