The line is at claiming a loss for tax purposes. Destroy the film if you like, but then you get no tax break.
There's a similarity with the "hobby loss rule". In order to be a valid business who can deduct business expenses like losses, you have to demonstrate that you have a "profit intent". That means that you make at least an attempt to turn a profit on your work. If you don't, it's considered a hobby and you don't get to deduct any expenses.
If Warner Bros is going to make movies just to delete them without even trying to sell them, that sounds like they're just indulging in a movie-making hobby rather than being in the movie business.
There's a similarity with the "hobby loss rule". In order to be a valid business who can deduct business expenses like losses, you have to demonstrate that you have a "profit intent". That means that you make at least an attempt to turn a profit on your work. If you don't, it's considered a hobby and you don't get to deduct any expenses.
If Warner Bros is going to make movies just to delete them without even trying to sell them, that sounds like they're just indulging in a movie-making hobby rather than being in the movie business.