When I turned in my iPad (Air 4) due to some issues with magnetic covers within warranty, I got a free replacement and a 90-day trial to Apple TV+. I watched Ted Lasso (all 3 seasons), Silo and Severance during these 3 months.
I’m not sure why you only got 7 days, but I would assume that Apple gives a longer trial to people who just got a new iDevice.
ps. I should mention that if I were to get a new tablet today, I would get one from Samsung.