https://wccftech.com/oxygenos-9-0-brings-android-pie-to-the-oneplus-6-includes-ui-changes-and-more/

OnePlus is rolling out the much-awaited Android Pie to their 2018 flagship the OnePlus 6, effectively making it the only non-Google phone (barring Essential) to get Android Pie. The device had an open beta going on for a while, and it was only a matter of time before a final release was rolled out. It gets the latest UI changes, battery improvements, as well as some other OxygenOS stuff like accent colour customization and Gaming Mode 3.0. Let’s take a look at what this update has to offer:

Related Leaked Build Gives us First Look at Android Pie on the Samsung Galaxy S9 Plus