The arrival of the 120 Hz oled panels for the next iPhone model would be exclusive to Samsung Display. The South Korean company it seems that it has been done with the total of the manufacture according to some reports leaked by The Elec. Logically this news is yet to be confirmed officially and it is not really known if they will share the manufacturing with LG or other firms but everything indicates that it will not be the case.
At the moment the iPhone 13 with this type of screen called LTPO OLED seems to be exclusively supplied by Samsung Display.
On the website iClarified they echo this news that seems to be only valid for the most Top teams of the following iPhone 13 Pro, that is, the Max. As with the iPad Pro models launched this year, the Cupertino company only adds the mini-LED panel on the 12,9-inch models, so something similar would happen with these. OLED displays with 120 Hz refresh rate for the top models of the iPhone 13 Pro.
As can be read on this website, Samsung Display will supply Apple with 110 million OLED panels this year for iPhones, while LG Display will take about 50 million screens and BOE will eventually manufacture about 9 million. It is the case that Samsung would have even considered abandoning the RFPCB manufacturing business last year because of how unprofitable it was being, but thanks to higher-end iPhone 13 Pro models this type of panel will continue to be manufactured.