https://www.techradar.com/news/oneplus-7-pro-features-are-being-brought-to-older-oneplus-phones-by-fans

When the OnePlus 7 Pro launched it brought with it some novel new features such as a pop-up selfie camera and 90Hz refresh rate, which we haven’t seen in many phones before.

It also included some unusual software, most notably screen recording and Zen Mode, and it looks like older OnePlus phones could be seeing these features early.