> All other users on our US cloud instance are opted in by default

Cool, cool. Glad to see that you are the arbiter of what your users have "opted" to do, and their input isn't required.

While we're at it, I'm going to "volunteer" your time to rebuild my patio this weekend. You don't need to worry about volunteering, I've done it for you.

If you send a postcard by Friday 5:00 PM, you can opt out of helping me with my patio. This is a one time offer; if you don’t, you have to help me every weekend for forever.