I am not talking about amazon knowing it. Amazon offers shops for businesses, where a business directly sells goods to their customers using amazon as a transaction platform. Those shops send the goods directly to their customers (Sometimes it comes from an amazon warehouse as well tho). If the first case is true, mullvad would send me the card directly, so they would know I bought it, which makes the card obsolete in my view.
But maybe they don’t send it themself and the cards are all just sitting in a big warehouse. Either way, to me it’s not 100% a given that they couldn’t at least in theory know who bought it.
I am just playing devils advocate here btw, I am not really concerned about it.