This is upsetting. I currently use macOS with iCloud, FaceTime, iMessage, and App Store all disabled, and use Little Snitch to prevent the machine from communicating with Apple except for on update days, and then limited only to those specific update processes.
It’s possible that this will mean that the next macOS version will be unsuitable on privacy grounds, as I will then have to use a second physical device to prevent such network access. :(