It is and it isn't. I've noticed that the option of enabling notifications for my own flights is no longer available; but when I select "where is my plane coming from" it takes me to the inbound flight and gives me the option to enable notifications.

I still get notifications related to the flights I am booked on and by default those flights now show up in the flight status page, whereas they only showed up when I selected "track this flight" or whatever it was called.

The only thing I can imagine is that now by default, now you'll receive notifications specific to the flights you are on without actually having to go into the screen and enable notifications for those particular flights. Preboarding/Boarding, Gate changes, Delays/Xls, etc are autopushed to the device which is nice not having to either pull out my phone and/or constantly refresh the page.