It isn't Sony who benefits from pulling the movie. It is the theaters. If this movie was going to be a dud, Sony would make some money back, greater than zero r

It isn't Sony who benefits from pulling the movie. It is the theaters. If this movie was going to be a dud, Sony would make some money back, greater than zero revenue. All their costs are sunk. But the theaters would lose money relative to how much they might make screening a more popular movie. So the theater chains can use this as an excuse to cancel showing the release, which is probably a violation of some contract or agreement, but they can get away with it in this special circumstance.