Good to see them going in that direction.
For example, is there any mechanism to protect against de anonymization by sybil attack?
I'm looking forward to see how sybil attacks will be discouraged in the case where the attacker launches (or bribes) a coordinator. At the moment, Whirlpool discourages by not allowing you to select which round to join. Round selection is random. But, this is trust-requiring to Samourai users, as far as I understand.
Whirlpool is uniquely vulnerable to Sybil attacks since the attack victims pay the mining fees of the attacker.
Care to elaborate? If you're talking about the infinite remixes, then the honest users are also having their mining fees paid by an attacker. In addition, the attacker can't remove them from the coinjoin or join a round of their choice. They must keep spending coins until they join the round they want.