When you go into the edit mode of an entry, there is a gear icon right-aligned to every password field. For example, like this:
To me, a gear icon implies functionality related to accessing settings and most likely, something that may involve another screen to pop-up and allow me to configure something in more detail. I've seen gears used for dropdown button style setting menus as well, but it seems the vertical ellipsis is a more common symbolic representation.
However, I have never seen it indicate a destructive action, like completely overwriting your password with a randomly generated one. A destructive action that cannot be undone and occurs without confirmation via a prompt that occurs when clicking an icon that we've become synonymous with something so innocent. At the very least, a confirmation would be nice before I completely wipe out my password and end up having to go through the process of resetting my password with that service because I rely on 1Password to remember my passwords and now that password is gone. Even if I was already logged into that service, many change password sites require the old password.
I feel like it's probably common to click around after a new update and try to see what new features get added. "Oo, dark mode enhancements!" "Ooo, more preference options!" "Ooo, I wonder if they added more configuration to that password field... maybe like adding recurring reminders to reset every 6 months or something nifty they thought up? Oh no, that was the generate password button and I need to reset this. Crap!"
A gear icon is not intuitive here at all!
1Password Version: 7.2.1
Extension Version: Not Provided
OS Version: OS X 10.14
Sync Type: Not Provided