FB cannot afford to lose its Brazilian Whatsapp market share, I am guesstimating over 50% of its users in South America are from Brazil? Furthermore, integrations of Whatsapp to businesses (with or without a legal API) are already happening so there is high pressure to rollout a business oriented API and make the billions back, I am sure Brazilian numbers are key in the projected revenue stream. Given this, I dare to predict FB will just lift encryption for Brazilian users and blame it on their legal system. In the end, the average internet user couldn't care less about privacy; in fact, in developing countries users are much more concerned with saving money with free SMS and calls.