Apple has been developing Micro-LED panels which may be used in place of OLED for its newer model Apple Watch due for release in the second half of 2017, according to DigiTimes.
Micro-LED displays can be thinner, lighter, and also increase brightness and offer higher resolutions. The panels do not require backlighting like traditional LCD, with sizes from one to 100 microns. The production of micro-LED panels could be more difficult and more expensive thatn OLED panels.
It is still unclear why Apple would move away from OLED, but knowing that the tech giant has purchase LuxVue, an US-based Micro LED developer technology in May 2014 and set a laboratoy in northern Taiwan specifically for R&D of new display technologies back in April 2015, this may be a sign that the changes are more than mere rumors.
Micro-LED technology is not currently being mass produced, and difficult to build display panels of any size, so it's possible that rumors a 2017 launch could be a stretch. But if Apple is able to once again breakthrough with micro-LED, they will return to their days of glory when they became the first company to introduce micro-LED to the masses.