Meta is a common word used for gaming. It’s any action, strategy or method using anything that is best at the current state of the game. For example in the recent patches, UMP got so strong that eventually players were replacing most assault rifles to UMP. The common use of UMP was not because of its popularity. It was more about gaining leverage over the other players. After few patches UMP got nerfed and it returned back to it’s position where it was once before.
Though there is no specific meta in PUBG, that is mostly because it is a first-person-shooter game. Other genres such as MOBA(Multiplayer Online Battle Arena) games mostly have a meta that changes over the updates and events. The biggest example for this type of game is League of Legends and DOTA2. All the players have to follow the meta at some point to win games. This makes lots of people frustrated because they simply want to play the game and have a good time with friends. That is where games like PUBG have an advantage with casual players against more complicated strategy games.