Been using an app called Parcel to track all my packages. It works brilliantly, and even pulls in Amazon shipments automatically. However, if Wallet starts scanning through incoming email to pull in tracking numbers, that could take a big divot out of Parcel's business.
As for Spotlight, I've been an Alfred user for quite a few years now, but if the new Spotlight proves to be as good as it looked... well, that could do it for me. That said, Alfred's true core is power-user scripting workflow stuff that I'm not sure Spotlight can match. I guess we'll see.