According to display analyst Ross Young, Apple’s “iPhone 13 Pro” and flagship “iPhone 13 Pro Max” models due this year are expected to use LTPO display technology to enable ProMotion refresh rates of up to 120Hz for even fluid scrolling, greater responsiveness, and smoother motion content for tasks like reading, gaming, etc.

ProMotion improves display quality and reduces power consumption by automatically adjusting the display refresh rate to match the movement of the content.
Young reaffirmed the detail in a tweet that said he’d heard rumors about only one model featuring LTPO, which he says is inaccurate.
Heard some rumors in the industry and media that there would only be one LTPO model from Apple later this year. Can confirm that is not the case. Apple fans can relax!
— Ross Young (@DSCCRoss) April 16, 2021
At this point, multiple rumors have confirmed both LTPO technology and 120Hz refresh rates for the two Pro-level iPhone 13 models. 120Hz ProMotion displays were rumored for the iPhone 12 models as well, but Apple did not implement them and instead saved the feature for the iPhone 13 lineup.
MacDailyNews Take: The addition of ProMotion will make “iPhone 13 Pro Max” and automatic upgrade for us over our current, and beloved iPhone 12 Pro Max units – the best smartphone ever made.