Ghostbusters is a harmless movie, and sure, it should be allowed to be shown in China. The Chinese government tries to have way too much control over the lives of its citizens. People should be able to watch whatever movies they want to watch, and they deserve to have options.
The wording of this is really strange. It sounds like it was ‘denied’ a screening because it hasn’t been reviewed/approved by the censor board. I don’t understand how it can be ‘banned’ if it hasn’t been reviewed yet. Maybe they attempted to screen it without submitting it to the review board? I remember controversy when a World of Warcraft expansion had to be "censored" for its China release because of some issue with "zombies" and "exposed bones".
Ghostbusters is a mostly positive and uplifting movie that supports girl power. It is a great movie with some funny escapists tendancies that also promotes a positive message. The movie should be shown in China because people should be allowed to see some thing so entertaining and positive in nature.
The new Ghostbusters film has attracted an incredible amount of controversy within the United States - male viewers are outraged about the female-centered reboot. I don't think that a similar controversy would occur in China. There is really no reason not to show it there: international markets are usually a boon for a film's success.