Yes, one con I found but didn't write about is that this won't be even close to a "clean" label. Many ingredients and nutrients will actually have to be added to the product after it's made, which could turn off a bunch of consumers.

I like the simplicity of your idea. I was just reading an article that called for companies to take care of any waste their products generate. It's an interesting perspective that points out food is often not a reflection of its actual cost to society. Instead we have random crops that are subsidized for decades and grandfathered in. Food companies don't account for their waste, pollution, etc.