"The technique relies on a relatively simple search algorithm that searches through possible sets of rules that can best predict a set of frame transitions" so

"The technique relies on a relatively simple search algorithm that searches through possible sets of rules that can best predict a set of frame transitions" so, their script/app doesn't reproduce a game engine at all, it instead analyzes pixel arrays from video frames and maintains rules about how the pixel arrays typically transform from one state to another. this sounds more like a useful video analytics tool than an "AI that makes game engines". if i was responsible for the headline/marketing, i would've gone with "Artificial Intelligence Can Predict the Ending of a Movie" or something (as long as the movie is 8-bit and only has 256 possible colors!) in other words i dont think Unreal or Unity are worried about this tech.