Great analysis. However, it is much more likely that the directors sought inspiration from the video for Rockwell's "Somebody's Watching Me" which featured a Thriller-era MJ on the hook. In the video, MJ doesn't make an appearance but one can infer that he is the spooky aberration "watching" Rockwell. That song and video came out six months prior to "Ghostbusters" and due to both the popularity of MJ and the fact that 1984 was a very competitive year for movie soundtracks, it is likely thus was the case and all other occurrences were subcinscious.