[sneak]

With modern encryption protocols, this yields you nothing.

The feature is called Perfect Forward Secrecy, and protects past flows from later key compromise.

Wireguard supports this, which is what Mullvad uses. (For some reason, speculation about which is an exercise left to the reader, WPA in Wi-Fi still does not.)

[woodruffw]

Not exactly nothing, just not ongoing compromise. TLS session keys can be pretty long-lived; I don’t know how long-lived Wireguard’s equivalent keys are, but even a relatively conservative few minutes can yield valuable traffic and metadata.

(That being said, I think having your RAM frozen to extract ephemeral secrets is firmly in the “fully hosed” threat model, and is not a realistic model for 99.9% of users to plan for.)