So why is Facebook going back to 2011? According to Wong, the company is starting to lay the groundwork for integrated messaging across all its services. The company reportedly plans to unify its Whatsapp, Messenger and Instagram messaging apps, adding end-to-end encryption to ensure user privacy. They'll continue to work as standalone apps, but share the same underlying architecture. Facebook reportedly has thousands of developers working on the project, with a plan to complete it in late 2019 or early 2020.
The testing appears to be in early stages, and Wong said that the "Chats" section only has basic text, and no reactions, calls, video or photos. For that, "you'd still have to open the Messenger app," she said. Facebook will still keep all three apps, she believes, because "they serve different markets."
Update 3:01PM ET: Here's a statement from Facebook: "We are testing ways to improve the messaging experience for people within the Facebook app. Messenger remains a feature-rich, stand-alone messaging app with over a billion people using it monthly to connect with the people and businesses they care about most. We do not have any additional details to share at this time."