Announcing a plan to do something in future is not the same thing as doing it right now.
Fair point. But showing intention to perform blacklist is enough to make people doubt or even lose trust towards Wasabi Wallet/zkSNACKs.
It's not proof that it's already happened, but it's just quite hard to prove someone did get blacklisted, and impossible to prove that nobody got blacklisted.
Dude it's not hard at all if you want to prove something digitally, it's not like I am trying to prove when I had my first kiss, but there would always be people who will trust or not-trust.
It could be really hard when there are other reason to prevent someone from participate on CoinJoin process. For example, failed to sign transaction within time limit or attempt to DDoS the coordinator. I don't remember whether coordinator return message about why someone can't participate on CoinJoin process though.