The open world Western RPG from CD Projekt Red is not getting a PlayStation Pro Patch, as the studio game the following comment.
The PS4 version of The Witcher 3 will not be updated for PS4 Pro, CD Projekt RED has confirmed, instead choosing to focus its development resources on upcoming games Cyberpunk 2077 and Gwent
“Since we want to fully focus on Cyberpunk 2077 and Gwent, and converting The Witcher 3: Wild Hunt from a full HD game into a 4K one would be too much of a time and resource-consuming process, we decided not to release an edition of Wild Hunt supporting the new features of PlayStation Pro,” the developer said.
Considering how much work it might be adding new graphical effects to the PS4 version I can understand this decision. More so from their comment, as they want to work on future projects, not continue working on the one they recently fully warped up (latest DLC released not that long ago).
Sources: NeoGaf & VideoGamer