I'm pretty confident they make it intentionally hidden so you don't know until it affects you. For example, titling the FAQ "What happens to my backups when I'm away or on vacation?" vs "What is your external drive retention policy?"
I don't think it's hidden. Backblaze will warn you if it hasn't seen a drive in a few days, and right in that email is the heads up that the drive will be deleted. I thought it was also in the external drive management pane of the app. However if you just let Backblaze do its thing, and don't have warnings enabled, you might get got good.
