Supermassive Games announced on Twitter today that they currently do not have plans to optimize Until Dawn for PS4 Pro.
— Supermassive Games (@SuperMGames) November 8, 2016
Until Dawn is a cinematic horror game that released last year to critical acclaim, and recently got a spin-off in Until Dawn: Rush of Blood for PlayStation VR. While it is unfortunate that it will not be getting PS4 Pro support, Supermassive Games is most likely looking to the future and focusing on their next game.
Until Dawn is a PS4 exclusive. The PS4 Pro will release on November 10.