A small, minor update is currently rolling out to the Chrome OS Stable Channel this morning. The update is build 64.0.3282.190 or 64.0.3282.192 (Platform version: 10176.76.0 or 10176.77.0 or 10176.80.0). Which build you will get depends on your device.
The update, as you can tell by that build number, keeps the platform in Chrome 64. The Chrome 65 build is next expected until next week on March 13th. This rather is a midstream bug fix and security update build. This is also the third Chrome 64 release for the platform.
The release notes for this new build are pretty thin as is normally the case for these midstream releases. In fact, the Chromium team did not link to the Git hub for this release indicating either the updates are all very minor – likely the case – or there is a major issue found and they won’t release the links until after a percentage of users have updated. That’s unlikely but possible.
Either way, you can check for the update on your Chromebook by typing chrome://help in the omnibar then checking for the update. If it is available for your device, it should download and after a restart of the browser, be applied.
For reference, my Google Pixelbook received the .190 build and 76.0 platform build this morning when I updated.