Speaking with MP1st, Piotr Pawlaczyk, Lead Level Designer for Techland, was quizzed about an upgrade or native version of the original Dying Light, to which they he replied:
Right now we are focusing on the release of Dying Light 2 Stay Human and other projects. So nothing to say at this time but we hear our fans and we know they are waiting for this kind of information.
Dying Light is one of thousands of PS4 games that are backwards compatible with the PS5, but its performance is capped at 30 FPS.
Techland is currently working on Dying Light 2: Stay Human for PS5, PS4, PC, Xbox Series X/S, and Xbox One, which is due for release on December 7, 2021.
[Source – MP1st]