Google can figure it out. I order something, i get cards in Google Now telling me exactly what i ordered and its shipping status, without any interaction on my part. It just happens.
If microsoft can't figure out how to do this, fine. But if they're going to pop up notifications saying "hey, i can track packages for you", they should be at least sort of on par with the competition.
I don't think I've ever seen it work as well as just going to the delivery services website, however - so it's critical that it's relatively bug free and low-overhead.
What if you buy a package from Amazon and the tracking info goes to your outlook.com email? That'd be a fair comparison here. (maybe simply forwarding the email from Gmail to the outlook.com email associated with your Windows account would be sufficient?)
Now what tells you this doesn't work with emails received in your outlook.com mailbox?
Or do you expect Windows to read all your Gmail's email somehow?