WhatsApp's business directory is now live in São Paulo to start, so it may be a while before it expands to a wider audience. The company plans to target India and Indonesia as its next locations, though there's no timetable for when it might launch in either region.
While this doesn't mean ads for businesses are coming to the app any time soon, it does seem like WhatsApp is planning on including advertisements sometime in the future. According to Matt Idema, Facebook's vice president of business messaging, “There’s definitely a route on ads, which is Facebook’s core business model, that over the long term I think in some form or another will be part of the business model for WhatsApp." That might not be the sentiment users are looking for from the company, but considering its owner, it shouldn't come as too much of a surprise.