Yeah, I wouldn't call it very personal when you know that Microsoft will be jerking off to all your data

How is this at all like having your own AI…

There's a certain logic to this. The more useful a personal AI is, the more it knows about your activities, so as to master helping you do them better. I'm not saying I like this new Microsoft feature, but the underlying logic is not exclusive to them - it will be everywhere else in the world too eventually as AI grows.