https://www.cnet.com/news/future-iphone-third-camera-for-ar-says-analyst/

A 2019 iPhone has been rumored to have three cameras. Now an analyst report speculates that one of the cameras will have a telephoto lens, while the other two will work together to perform depth mapping for AR (the same way 3D cameras do) rather than a dedicated 3D-sensing module. 

That's according to Lu Jialin, a Deutsche Securities analyst, as quoted in China's Economic Daily (using Google Translate) on Monday. The rumor follows on the word that next year's iPhones might all have OLED screens.