yeah, because it's a public list. same with follow lists. i'm not gonna bother myself with that at this point, if a relay is public readable a lot of social graph can be inferred in analysis. concealing this would require a specification for privileged forms of these lists that can only be read by the authors and the relay
Discussion
also, muted npubs of malicious persons don't even care about it, except in as far as they have been designated malicious by someone.