Ghostbusters News appears to have connected the dots and revealed that the song was used in a re-worked form in a different movie starring Dan Aykroyd:
A reworked rendition of the rejected Ghostbusters theme song appears on 1987’s Dragnet soundtrack
Hah, even with the new lyrics you can hear where the “Ghostbusters!” used to be in the chorus.
Still a load of “meh!”.