If a coin is private, how could Chainanalysis refuse it?
Not sure how I am supposed to answer this question. By
doing it? Seeing that the private coin isn't in their possession and therefore blocking it from joining? We've seen numerous examples of people depositing coins in CEX and getting them refused due to blockchain analysis deeming them illicit. Coins coming out of mixers, coinjoins, etc.
What message did your client say when you tested a Sybil attack against it with your coordinator? I'm wondering how you came to that conclusion.
I came to that conclusion, because I searched the source code and I found no warnings that have to do with Sybil attack. In fact, the word "sybil" does not exist in the client:
https://github.com/search?q=repo%3AWalletWasabi%2FWalletWasabi+sybil&type=code. Can you direct me to the part of the client's code that warns the user about coordinator attacks?