Sincerest apologies for any Wi-Fi Issues — February 23rd - sorry from Google
WiFi Device Just Factory Reset on It's Own - Google forums thread
Primary onhub flashing blue self one of many Reddit threads on the topic
My Google Wifi just factory reset itself without my intervention another ressit thread, this one from the GoogleWifi subreddit.

Whatever the cause of the outage, this is a black-eye for Google and Cloud managed/controlled routers and devices. Maybe now is a good time to pickup some unwanted Google/OnHub routers