According to a report from The Verge, Facebook’s CEO Mark Zuckerberg revealed during the company’s Q4 earnings call that they are still in the early stages of thinking about this. “The integration that we’re thinking about, we’re really early in thinking through this. There’s a lot more we need to figure out.”
There is no word on when this will happen (if at all), but it looks like 2019 might not be a possibility. Zuckerberg also highlighted some reasons as to why a unified system could be beneficial for users. He mentioned how users had to swap between apps for different tasks, like how someone shopping on Facebook’s marketplace would need to jump to WhatsApp to reach the seller.
He also mentioned how combining its services could serve as an equivalent to iMessage that could offer up more functionality and security. We can’t really imagine how a unified service will work at the moment, but as Zuckerberg states, they’re still very much in the early stages of figuring it out themselves.