My domain of 800+ users had one unhashed user. It was an account I created for testing something then suspended over two years ago. It never completed the first logon. I have many newer users that have not completed a first logon, yet their passwords are (apparently) hashed.

They said users created through admin console are affected. The might explain my nearly zero count. I've used GAM to automate creation for a very long time. We are a high school school so we churn about 1/4 of our user count every year.