The recent OnePlus 7T / 7T Pro have a Fuild AMOLED screen with a 90 Hz refresh rate. The same frequency was chosen by Google for Pixels 4. The Chinese manufacturer could bring the value to 120 Hz with the next one OnePlus 8 Pro.
Indiscretion comes from a well-known leaker, considered quite reliable. For the OnePlus 8 the frequency of would instead be confirmed 90 Hz. OnePlus will certainly allow you to set the traditional 60 Hz, as the permanent use of 120 Hz will lead to excessive battery consumption, in addition to the fact that a similar value is not necessary for all contents. The greatest benefits are achieved with fast-moving images, such as games. Videos are usually recorded at 24 or 30 fps.