Today’s AI upscale/enlarge programs do some crazy things. Here is an example of enlarging bad quality cover art from Famicom cartridge. The result is photo-realistic female face.
I guess in near future there might appear specific AI algorithms and it would be possible to upscale a sprite into anime character. So imagine a realistic anime cut-scenes from Ninja Gaiden series. Or the final picture of Miria in The Guardian Legend.