If no, i doubt anyone can provide proof unless someone who works there become whistleblower.
Or someone could simply do one easy experiment with sending their coins to wasabi coinjoin and see what happens... if bomb will explode, special forces storm your apartment, and your transaction gets rejected for some reason.
It's not that simple. Even if you unable to join CoinJoin process, there are other reason than your UTXO blacklist which mentioned on their blog. See
https://github.com/nopara73/ZeroLink#d-dos-attack.
One more problem I faced is that I was not able to connect Trezor device with wasabi wallet, and I was not the only one with this issue.
That's true, there are similar reports on WasabiWallet GitHub.