I once bought a TAP flight (for someone else) on Trip dot com. I was impressed. I got very frequent reports about the status of the flight (check-in open, boarding at gate X, flight departed, flight landed). I had never been so fully informed about the flights I booked for myself direct from airlines.
P.S. I was notified by Trip dot com, not by the airline. In order to get notifications you may have to run the app on your smartphone, even if you booked through the browser.
Why book through Trip dot com and not directly from TAP? Because TAP didn't know me yet and I was in a hurry. Had I tried to book direct on the TAP website, who knows what hitches there could've been (credit card rejected, addresses in wrong format etc.). As it was, since Trip dot com knew me and my credit card already, all I needed to supply was the data of the person I was buying the ticket for.