Dying Light: The Following - Enhanced Edition is being worked on by developer Techland, with the Enhanced Edition being a new package that will include all of the content from Dying Light, as well as something new.
The Following expansion will include all of the previously released content and DLC, but the Enhanced Edition will spruce up the visuals and draw distance in Dying Light, as well as improve the performance on the console versions of the game, improve the overall gameplay, and more.
Techland has been working on Dying Light: The Following - Enhanced Edition for 1.5 years now, but have been unable to get the Xbox One version of the game above its current rendering resolution on the normal version of Dying Light: 1536x1080. The PS4 version of Dying Light for comparison sake runs at 1920x1080. During an interview with GamingBolt, Lead Producer on Dying Light Tymon Smektala said: "It's still 1536×1080. We believe a smoother frame-rate is more important than the exact resolution".
So while the rendering resolution won't change, we should see an improvement on the frame rate side of things. Not only that, but Smektala was asked about DirectX 12 support, to which he replied there's no immediate plans, but they are definitely looking into it. He continued: "We've been tinkering around with DX12 tech for a bit. [However] there is no immediate plan for an official DX12 release before we are done with Dying Light: The Following. After that, we'll go right back into tinkering and see what we can do".