The OnePlus 7 and 7T series will begin receiving Android 11 and OxygenOS 11 from December, according to a company spokesperson. It is unclear whether these will be beta or stable builds, but the likes of the OnePlus 7 and OnePlus 7T Pro will at least get a taste of Android 11 before the year is out.
https://www.notebookcheck.net/OnePlus-confirms-December-arrival-of-Android-11-and-OxygenOS-11-for-the-OnePlus-7-and-7T-series.498123.0.html