Non sequiter. All the government could force Amazon to reveal is that you purchased that gift card. They can’t A) prove that you used it vs handing it out as a gift B) tie the purchase to a specific Mullvad account.
The government do get a limit number of potential users. Can this together with fingerprints, ping latency(?) etc. be used together with amazon info to narrow down the vpn user (in theory) or is that impossible?
For example, if mullvad only had 5 users in separate continents, could one measure the latency and crossreference with a amazon buy history to identify the vpn user?
To a prosecutor, that means they have a conspiracy or even RICO case on their hands.