As The Wall Street Journal reports, the end of LCD panels in iPhones looks to be near due to a couple of major factors. The first is the iPhone XR, which is Apple's only LCD-using iPhone model this generation. It hasn't sold very well for a number of reasons, with cheap batteries and China being the two biggest.
Sales are so poor, Japan Display who supplies the iPhone XR LCD panels and relies on Apple for a big chunk of its income, is in serious trouble. The Japanese company has relied on several cash injections from a government-backed fund and shareholders to stay in business, but now it is considering selling a 30 percent stake of the company in order to survive.
The other big factor is the 2020 iPhone. It is thought that the iPhone as we know it may be coming to an end. 2019 will see the usual iPhone line-up refresh, but 2020 is expected to be different. A radical design shift could happen, and that requires flexibility in the components being used. OLED panels can be produced to conform to unusual shapes, where as LCD panels only offer variations on a rectangle. With that in mind, if Apple does create a new form for the iPhone that isn't just a glass-fronted slab, OLED will be the only viable display choice.
It's usually the case that where Apple goes, the competition follows. We've seen that most recently with the notch appearing on displays (although it should disappear again this year) and more companies dropping the headphone jack. It therefore seems likely that if Apple drops LCD so will others, which makes for an even more hostile environment for LCD manufacturers such as Japan Display. And if you think LCD is safe because laptops are still a thing, think again, HP and Lenovo brought OLED laptops to CES this year.