Apple could adopt new power-saving backplane technology in the future. What this means is they could get better batteries which last longer.
What the backplane does is turning on or off individual pixels. This way it's better for the resoluton, refresh rate and the battery life.
We'll try not to make it too complicated. The current OLED displays uses standard backplane technology, called LTPS TFT. The new ones will probably get LTPO TFT. Easier said, they switch from low temperature polysilicon thin- film transistors to low-temperature polycrystalline oxide backplanes.
LTPO will save up to 15% in power consumption vs LTPS. This is really needed because display sizes increases and power consumption also. IHS says that Apple also may be interested in developing LTPO technology to gain more control over the OLED displays components, because LG and Samsung maintain exclusive control over the process.
Also IHS thinks that Apple will require their manufacturers (Samsung and LG) to switch to LTPO technology. They also say Apple will probably first get them for the Apple Watch and then later on also on the iPhones.