Bloomberg reported back in November 2014 that Foxconn is building a new $2.6B worth of display factory whose product could be exclusively for the Apple Inc. The headline was quickly changed to eliminate the reference to Apple, the piece still strongly hinted at Apple being the only client of Foxconn. This latest report states that the factory is only manufacturing OLED displays.
Even if the factory is making only OLED displays or the manufacturing in exclusively for Apply, that also doesn’t necessarily indicate you will probably have OLED displays in next iPhone. Apple has already announced that the Apple iWatch will make use of OLED displays. Currently LG is now the major supplier of Apple Watch displays.
While OLED has quite a few advantages over LCD displays, it is more expensive to manufacture, so a switch is not just one that Apple would make with no careful cost-benefit analysis.