http://o54hon2e2vj6c7m3aqqu6uyece65by3vgoxxhlqlsvkmacw6a7m7kiad.onion/en/blog/2019/11/3/faster-rotation-wg-keys-and-static-ip-addresses
In the latest Mullvad App (Linux, macOS and Android beta) you can manually rotate WireGuard keys and internal static IP-addresses. The rotation will take a few seconds to propagates to all servers. Desktop Settings, Advanced, WireGuard Key and press Regenerate key. Mobile Settings, WireGuard Key and press Replace key.