That is why "most" shoot raw. so they can adjust everything in post.This is not true. Red and the Blackmagic cinema cameras shoot in RAW and they also shoot very flat. I am interested in a knowledgable answer to this question too, as I want to expand the dynamic range of my DSLRs.
Same is true for video if raw is a option then there is no need for cinestyles.
Short Answer: The appearance or look of RAW files are always the result of some kind of software or hardware processing. It is completely up to the processing of said hardware or software that determines how the image/video looks.
All RAW file types are different (some more than others and some less than others), but in both still and video RAW files contain the uncompressed or compressed Bayer Sensor Data along with some other items (metadata related to camera settings, type, etc). In order to see a preview from either requires demosaicing of the Bayer Sensor Data. So depending on demosaicing process (along with any other processes that are carried out along with it... white balancing, noise reduction, etc) you end up with an actual image (or preview).
RAW files from still cameras tend to have a processed JPEG within the RAW file wrapper for fast previewing purposes. So your camera that has essentially provided the demosaicing and other processing for previewing on the back of the camera. This is why changing your Picture Style while shooting RAW will still change what the preview image looks like on the back of the camera. Also, once you open your RAW image in software the software is providing the demosaicing and other processing to render the preview you see on screen.
RAW files from video cameras typically don't have transcoded previews within the RAW file wrapper for fast previewing and therefore require some sort of transcoding to preview. When previewing the footage on camera the camera is again doing the work while software does this if previewing on a computer.