The popular image of Satanism nowadays is a Christianity turned upside-down, basically the image created by LaVey. And the popular image of a satanist is a drug addict violent rocker who likes to paint pentagrams and kill animals "in the name of Satan". Also here Satan is the same character like is in Christianity, just turned into an archetip of rebellion and anarchy, which has nothing to do with His real meaning. So if that movie will just ridiculate the modern satanism, it won't really damage us in any way, it will just increase the ignorance in people regarding satanism in general. Most people are not aware of Joy of Satan and most people are not aware that the real satanism has it's origins in the ancient civilizations. When they will discover this, they won't give a shit anymore on such movies.
And definitely they won't ridiculate spiritual satanism because this might make millions of people be actually interested in SS and this community, a thing which they try to avoid because even the negative advertise brings people here, this is why Joy of Satan doesn't have even a Wikipedia page.