After the launch of One Plus 7 Pro and OnePlus 7T Pro with 90Hz Fluid AMOLED Display now the rumor mills suggest that the OnePlus 8 Pro with 120Hz Fluid AMOLED Display.
OnePlus 8 Pro with 120Hz Fluid AMOLED Display

A well-known leaker called Max J. has tweeted to say that the next high-end OnePlus smartphone, i.e. OnePlus 8 Pro, would feature a massive upgrade. The caption in this tweet (attached below) reads “Be a pro,” which indicates that OnePlus 8 Pro will come with a super smooth 120Hz display panel.
Be a "pro". pic.twitter.com/h4UwnOXn8H
— Max Jambor (@MaxJmb) November 7, 2019
If this turns out to be accurate, the OnePlus 8 Pro will be the first smartphone to feature a 120Hz screen from the Chinese phone manufacturer.

The OnePlus will be having a Qualcomm chip Snapdragon 865 processor which might launch this month. The device will come with four cameras at the back and a punch-hole camera in the front.
This will be the next phone with 120Hz display as ROG 2 has a 120Hz screen which launched this year. The ROG 2 has an HD+ camera so the OnePlus 8 Pro will have Quad HD+ screen.

At the OnePlus 7 T launch event, OnePlus announced that all of its phones would sport a 90Hz display as a regular forward. For the Pro model, therefore, it only makes sense to have a higher refresh rate screen, considering that it will certainly demand a premium over the regular model.
OnePlus 8 Pro Video:
[su_youtube url=”https://youtu.be/lZoDd1vMz2o”]
As of now there is no information about when the One plus launched might happen, so everyone looks forward to when they might launch next year.