I think/hope any server running in cracked mode (online-mode set to false: https://minecraft.fandom.com/wiki/Server.properties) won't have this chat reporting. At least, it would surely be broken for anybody joining a cracked server with a cracked client. Maybe legit players on cracked servers could still be reported, if their client and the server both pass through the chat signatures.
As of right now, the chat signing (which was only used for blocking certain players' chat from appearing to you) can be disabled by the server alone, or in conjunction with the authentication.
It is unclear whether that will remain the status quo.
