Although, this weeks planned update will not happen until early next week. PlayerUnknown has shared some intel on the upcoming updates for PUBG.

According to this Tweet a new animation is coming, for when a player drinks an energy drink.

Also, in this Tweet, he stated that a developer is working on a new gun. Details on what specific gun is being added are yet to be revealed.

Game Informer has revealed back in may, that two new maps would be added to the game in the future.
Details of those maps were reported on reddit today. An 8×8 km Adriatic Sea island with forests and a 4×4 km desert city-centric map with a canyon, river and villages.

Both maps will deliver a significant amount of variety, however there was no ETA on the maps release. But the gun will definitely be part of the next monthly update.