No good way to know for sure without operating one of the following
- mullvad vpn servers or discovery
- routing devices between your device and theirs
- TLA ops for said purpose

As an individual, we can only observe and speculate. One of the endpoints I was recently using is no longer there, raising the question as to whether a) ephemeral VPN in good faith, b) ephemeral in bad faith, c) im mistaken/imagining.

So the above I share without further details in case anyone else has experienced this in the past as well. 

 Thank you, will be on alert