Update : June 21, 2018 – It seems that Google has pulled the update. Users who managed to install the update before Google pulled it can perform a rollback if the stability issues are making your Chromebook unusable. Rollbacks do require a powerwash which may or may not be a reason to hold out for a stable update.
It looks like Google has begun the rollout of ChromeOS 69.0.3464.0 to users on the “dev” channel. This is actually a major version increase as all previous updates were part of ChromeOS 68. Lets look at some of the changes Google has packed into this release – fair warning, there is A LOT in this release and plenty of bugs.