It appears that perhaps disabling the cr-unsubscribe-notification module may be a workaround, but it's not recommended since there could be unintended consequences to that.
I'd love to see a recommended way from Atlassian on how to disable the "Don't notify me" button. If it's disabling this module, great. If not, an admin setting to control this would be fine. We just don't want our users opting out of notifications if we're trying to communicate with them.
This feature would be very nice. As an admin I want to decide for a project to hide or not to hide this option. In our case our customers are confused to have this option in the Service Desk Portal.