It appears that Microsoft isn't the only one involved in the recent privacy violation incident through the personal assistant service, like Siri, Google Assistant, Alexa, etc. Who knows the motive and reason behind this? Plus, you're going to disable Siri/Google Assistant on your mobile device over this situation, though?
To train the AI through data collection through various products like Cortana, Kinect and even Skype Translator engine seems to be a dangerous excuse or a lousy one. So, it looks like Microsoft might have lied or something that the Xbox One Kinect wouldn't collect data when the console was revealed at the time that the data collection thingy through Kinect resumed sometime later. I don't know if this may seem accurate or not but then again, who the hell uses Cortana on their computers and Xbox One anyway?
To disable Cortana completely from Windows 10 will be no easy feat even when there were feature changes in Windows 10 1903 update which separates Cortana and Search feature as well as the fact that Cortana will be on the Microsoft Store in the future. It may seem like an acceptable change but don't go asking us that don't we even use Cortana at all or something. The worse thing is, there's still lack of support for other unlisted countries but it shouldn't be difficult asking Cortana something in the same vein you ask Siri or Google Assistant which is obviously more popular.