https://wccftech.com/iphone-14-pro-could-use-ugraded-ltpo-screens-potentially-for-always-on-functionality/

The iPhone 13 Pro and iPhone 13 Pro models were Apple's first flagship smartphones with a variable 120Hz ProMotion display. We are expecting the iPhone 14 Pro models to come with the same high-refresh-rate panels but with a broader variable refresh rate spectrum. This could give Apple room to introduce an Always-On display on the iPhone 14 Pro models. Scroll down to read more details on the subject.

Apple used an LTPO panel on the iPhone 13 Pro models to bring variable refresh rates to the table. This allowed the smartphone to preserve battery life and offer enhanced battery life. On the current flagships, the ProMotion display offers a refresh rate between 10Hz and 120Hz. In contrast, Samsung and Oppo use LTPO displays that can drop as low as 1Hz when the screen is left idle.