Try coding something out in iDrive...like the warnings. I had the same issue as you when CarPlay showed up and I restored those warnings which restarts the iDrive/headunit and it came back.
I consider an OTA update to be any data that updates information on the car over the air, whether intentionally or not, software updates or credentials information related. CarPlay would have never been removed without the information traveling (over the air) and updating the car. And with that...
Do you think someone entered each of our garages at night and turned off Carplay manually, and then re-entered and turned it back on manually? I don't understand why this is so difficult for you to grasp. ?‍♂️
You stated it had nothing to do with OTA updates, which is absolutely wrong. It had everything to do with OTA updates, which has caused issues with BMW's CarPlay features more than once in the past.
Yeah, I could see that being the case. But usually, at least for the corporation I work for, these types of issues are considered production outages and are addressed immediately.