This has been around for a while in research papers. Getting people's pulse rate, and even blood pressure from videos.
Other things you can get from videos, electrical interference to determine which power grid somebody is using. Noises in the background can be mapped as well. So uploading a video deanonymizes you quite well, for properly motivated investigator.
In the escalating war against deepfakes however it will just be part of the arms race, and new deepfakes will now include those fluctuations.