I think the issue here isn't that they are deleting the movie, it's that they're deleting other people's work.

Remember, a corporation is a group of people joining together to create something they couldn't individually. Yes, there's a bunch of contract law we pile on top of that to make the concept borderline worthless, but bear with me.

If the employees created the movie, and the broader corporation declares it a failure and attempts to write it off, the people who created it should then be given the copyright or the copyright should be revoked such that those individual artists can do with it as they please.

Anything else is just someone coming over and stomping on your sandcastle because employee contract law is insane.