No, blockchain analysis has *always* had those coins "on their radar", getting rejected from a coinjoin does nothing to change that.
Strawman. Funding chain surveillance does help them continue their operations. For every unsuccessful coinjoin, they have a set of non-private UTXO. For every successfuly coinjoin, they get funded by Wasabi. Win-win.
Blockchain analysis is going to notice what the owner does with the Bitcoin no matter what.
Unless of course you had not given them the permission to reject certain UTXO from registering to the default coordinator. Now blockchain analysis can effectively intervene in the coinjoin.
So having a suspicion is enough. One would think that there should be more to it than just suspicion. When zkSNACKs receives a negative evaluation for certain coins by their blockchain analysis partners, do they care about the reasons? For instance, does blockchain analysis present solid evidence, suspicion, or at least a gut feeling that something is not right?
I don't know.
Wasabi knows nothing about blockchain analysis apart from how to buying their product.
