At least one of the 2018 iPhones would have the LCD panel.
There are rumors flying right now that Apple is working on a new lower cost iPhone, for 2018 that will ditch the glass back design of the iPhone 8 and iPhone 8 Plus and use metal like last year's iPhone 7 and iPhone 7 Plus.
It has been reported that Apple will offer a larger 512GB version of both the updated iPhone X and new iPhone X Plus, as it looks to boost sales among premium users.
Sources told Nikkei that Apple was also planning to release two iPhones with OLED screens. The final size is yet to be agreed but its will be either 6.2 or 6.3 inches. But Apple will be able to lower the cost of the iPhone, making sure consumers are not left completely out of an option to upgrade to the latest iPhones next year. The benefits of OLED displays can be extended to moulding into curved screens and even foldable displays, which can be useful in the future iPhones.
But it seems that Apple is not ready to bid farewell to LCD screens yet. A South Korean media outlet recently reported that Cupertino signed an OLED supply deal with LG Display. Casetek, a subsidiary of iPhone 8 manufacturer Pegatron Corp., could be selected to make the LCD iPhone.
Turn it around. Oops! Careful not to touch the bottom lens
Apple's latest flagship - iPhone 8 and iPhone 8 Plus - came with minor design tweaks compared to their predecessors and the biggest change was the glass unibody design. A second Nikkei source said Casetek has already been "experimenting with new casings for the LCD-equipped iPhone". Casetek has close links with its parent company.
Alongside this metal-backed iPhone, the source claims Apple is tentatively planning two new OLED handsets, one of which would be around 5.8 inches (like the iPhone X, which is now Apple's only OLED phone) and one of roughly 6.3 inches.
The two upcoming OLED models will be similar to the current iPhone X and will sport the same True Depth camera system, according to Nomura.
This will also reduce dependence of Apple on Samsung that is the only company to supply OLED displays in bulk to meet iPhone X demand.