Let's ignore whether there are courts involved in the original blocklists or not, compartimentalizing the discussion. Once a blocklist has been established, I think it's sensible to ban a website that publishes the blocklist:

DNS are precisely a mechanism to find websites based on names, and a list of blocked websites would serve essentially as a DNS, so it's clearly circumventing the original purpose of the blocklist, asking for a list of the blocked websites is an oxymoron, publishing a website that displays that is an oxymoron, and the block of such a website is sensible.