https://arstechnica.com/gadgets/2017/10/android-8-1-developer-preview-hands-on-everything-new-in-googles-latest-update/

Google gave us 64 days to get used to Android 8.0 Oreo being the latest version of Android. While zero third-party OEMs have upgraded to the latest version, Google is already dropping a developer preview for the next version of Android on the world. Two days ago it released the Android 8.1 Developer Preview, and after a solid day of trying to flash it, totally bricking a Pixel 2, and later having Google pull the update files because they didn't work, we're here to report what Android 8.1 is actually like.

Like most of the .1 releases these days, it's full of some minor-but-important updates that probably just weren't ready in time for Android 8.0.