I would consider making a new Amazon account but I have a feeling that new users probably get the new API.
dizziepanda
I created a new Amazon/PrimeVideo account (30 day trial) in Europe (not Germany)

and I get the default (old) layout, that still works with SF

As a result, I now have 4 out of 4 accounts with the old layout.
Ergo: It is random, so it has nothing to do with the age of the accounts.