When removing all labels/devices from a managed installed, a warning appears with "You have not limited this distribution to any labels or devices. Are you sure you want to deploy to all devices?" with the option to choose Yes or No. Choosing Yes does not push the install to all devices as the warning box seems to indicate it will. The install will not push to any devices.

My thought is no warning or a warning "you have chosen not to install to any machines" or something similar.

See case 3260078 for more details if needed.