AotC was digitally shot in 1,5k… So there is really no need to restore it in 4k.
It was indeed shot at less than 2K, however motion picture film should still be scanned at 4K or more. The reasons being many, but in broad strokes: digital video resolution signifies the size of the ‘container’ that contains the image. During film-out the digital image on any given frame is printed onto a piece of film, and film is a very different ‘container’ than digital. These two types of ‘containers’ are a lot different than any consumer facing publications explain. They often explain that film’s resolution equivalent is somewhere around 4-6K, but that is a bad analogy because the two systems are fundamentally different, i.e. Film’s grain structure, and thus image structure, is continuous, whereas digital is discreet. The image does not retain its discreet nature once it’s on film, it is now rendered by film as continuous. So in order to capture the image as best as possible, a higher resolution is needed. I’m not suggesting that the image ‘gains’ in quality from the film-out process, I’m saying that to transfer a continuous film image to digital, there is ‘loss’ of spacial resolution if you scan at say, 2K. Basically film and digital are not 1:1, in fact they are far from it. In other words, whether an image on film came from a digital file film-out or an optical/photochemical process, you lose quality by scanning at lower resolutions. The size of these losses is debatable, but remember that the pixel resolution of an image is only one part of its image resolution, especially when transferring back and forth between mediums.