PUBG seems to have DirectX 12 support in the future

13.2 Update, which will be released in the main PUBG: Battlegrounds cluster on September 8, features a new option to switch the DirectX version in the graphics settings. Two options are available:

• DirectX 11 (default)
• DirectX 11 Enhanced

The latter is in beta status (the developers do not guarantee the stability of this option). It allows you to get better graphics/performance.

Also, PlayerIGN dataminer found mentions of DirectX 12 in the game's files, which could be an indicator that the developers are planning to add support for the twelfth version in future updates.