About a month ago, we learned that Sony was developing a major new feature for their PS4 Pro called Boost Mode. The idea was that Boost Mode would enhance the performance of games that didn't have a PS4 Pro patch that were released before the new console came out. The new firmware update containing Boost Mode is currently in the last phase of its Beta testing, meaning it's almost ready for release. A PlayStation support specialist confirmed to a Reddit user that the firmware update would be coming out tomorrow.
There is still no official word from Sony, so take the rep's word with a grain of salt at this point. That said, the firmware's Beta testing has been running for the last month, so it stands to reason that it should be ready very soon.
Bloodborne is one of the biggest games shown to have a marked improvement in performance due to the Boost Mode while Assassin's Creed: Unity appears to run incredibly smooth considering its troubled past.