There have been plenty of headlines written in regard to smartphone owners waiting to receive an update to Android 10. However, smartphones are definitely not created equally, as an image of a Google Pixel 2 XL running on an alleged version of Android R has demonstrated. Android R is likely a preliminary name for Android 11.
https://www.notebookcheck.net/Android-10-update-headaches-skipped-by-Google-Pixel-2-XL-enjoying-Android-R.453010.0.html
All it means is that the owner built and installed AOSP master. Despite the "R" label, what it really is, is 10 plus all the external contributions that have been submitted since 10 stable was branched. Anyone can build and install this on ANY pixel or any of several other developer devices (like several 96boards SBC's).
Nothing to see here, move along.