According to Korean publication ETNews, Samsung is aiming to supply Apple with its latest Y-OCTA OLED panels for Apple's 2019 iPhones. Y-OCTA (or Youm On-Cell Touch AMOLED) is Samsung's term for its on-cell touch flexible AMOLED technology.
Y-OCTA panels are thinner than Samsung's previous flexible Add-On Touch panels as the touch sensor is deposited directly on the encapsulation (TFE) layer. The optical features are also better as the touch layer is below the polarizer and enables the use of a non-ITO grid, there's no need for a support film (see image above) and the number of layers is lower.