Every image sensor is unique as every pixel in sensor has different sensitivity. I don’t know how much information is lost when raw goes to jpeg but linking two pictures to same camera is possible if there is enough information. All cheap sensors used in phones and such has dark or stuck pixels which are corrected by software and that also leaves marks in picture.

Maybe related: https://lemmy.ml/post/56181 Facebook has a patent for uniquely fingerprinting cameras based on the pattern of dust and scratches on the sensor