This is unironically a brilliant idea, which is why Hollywood will never make it without completely bowdlerizing or bastardizing it. I could perhaps imagine a grimdark adult comedy version of something like Chicken Run or Free Birds where the animals' rebellion/escape in what would have been act 3 fails in the film's prologue and we fast forward to years after they were slaughtered and they plot to haunt the people and household pets who ate them from beyond the grave, similar to Sausage Party's treatment of Pixar films about talking animals and talking inanimate objects.