Before the recent update to my SHield Pro, there was a bunch of streaming content that did not work with the AI upscaling. Now it works with most of it on my 2019 SHield TV pro boxes.This is not quite correct. Most movies are photographed at 24 fps and most television shows at either 24 or 30 fps. Even if the app outputs them at 60 Hz, they are streamed from the provider at the original frame rate to save bandwidth. The AI Upscaling feature takes place early in the signal chain before the frame rate conversion. I have the Shield tube, and its AI Upscaling has worked on pretty much anything I've watched, which is easily apparent from the edge haloes it creates at the higher settings.
The 30 fps limit is more of an issue for gaming than for watching TV shows and movies.