It is simple. They are ignoring Paul Feig' s work.
Ghostbusters, Ghostbusters 2, Ghostbusters the Videogame, Ghostbusters 2020
Yup. The actors tried their best to save that turd of a script.
Was there even a script in Feig's reboot? The problem was that it was really more of a series of improvised skits than a coherent film.
Feig really wasted the talent that he had on hand.
That said, the updated remix of the theme song was solid. Hopefully that gets a proper release at some point.