The developer of Unrecord should never have shown off what he made or how he did it. The market is already flooded with this stuff, to the point that if Unrecord ever actually releases, the novelty of its style will be lost in the sea of mediocrity.
What is Unrecord really doing that's special? It just looks super realistic; which is mostly due to Unreal 5 and these hyper-realistic graphics were shown in other tech demos like The Matrix city or the Japanese train station demos.
Camera movement and perspective can have a huge impact on selling the images as "real". You can have a drone hover over a race car, and it will look fake, because your brain tells you it's a video game; "Here's to You" from the beginning of MGSV: Ground Zeroes still looks better than most cut-scenes because it emulates a person holding a camera.
Just to be clear, Unrecord (the game this cyberpunk mod is based off of) is a standalone game. It's also straight up copaganda, so I could give two fucks about the original dev. Besides that? There's no real benefit to keeping his technique to making the game's art style a secret, it's a good thing that the information is freely available.