This news is likely to displease regular players. With update 12.10, Fortnite has implemented a new feature on Chinese server that will change the gaming experience.
From now on, when a minor plays more than 3 hours in a row, the amount of earned XP will be halved and challenges will be disabled. More importantly, if the game session exceeds 5 hours, the player will no longer receive any XP at all.
This addiction health warning seems to be what motivated these changes on the Chinese server. In reality, it's unlikely that such restrictions will occur on our servers: firstly because no law in America or Europe forces publishers to be so strict, and secondly because Chinese servers are relatively independent from others — they sometimes have their own events and changes in-game.
It should be noted that these files have also been collected by American and European dataminers.
Also, if game sessions are too long, warning messages will appear on the screen. Here is one of them:
"You have been online for 3 hours accumulatively. The in-game gainings will be lowered by 50% from now on and challenge progress has been disabled. For your own health, please log-off and get some rest. Appropriate physical exercise is good for your body."