That was my thinking. Maybe we have giant silos of cacao, and those are dwindling, although I lack the imagination to think this is literally true. The whole premise looks like a reason to raise prices and profits.
If the world is eating more chocolate, it means the world is getting richer. Not many in China would be eating chocolate regularly 20 years ago, Same could be said of other areas.
Regardless, the math doesn't add up, particularly the future estimations of us consuming a million tons more than we make. The only place you see that kind of math is typically in the Ministry of Truth.