Using pitch in inches used to make sense when all airlines had very similar seating, but now the design of seats, and the thickness of the seats, vary quite tremendously particularly in Europe. When you walk into the Economy cabin in the A321LR you can immediately see the difference between the Plus and normal seating, there is clearly extra space. If I was a larger single traveller then I'd be tempted to pay the extra for them (though they are a free perk for TAP's own Gold status passengers). If the flight overall isn't too full, you are also more likely not to have someone sat next to you since TAP fills up the aircraft from the back (in broad terms) for the majority who don't do advance seat reservations. That said, it's definitely economy seating, it's not a Premium Economy service by any means.

There are some photos in this thread though they aren't entirely helpful.
GUIDE: TAP Air Portugal Airbus A321LR (A321neo LR) long haul, flat bed J