I'm not sure what you mean by "leak your IP" since IP address is always how you communicate. I guess you mean you no longer have a 192.168 or a 10. address that is "hidden" from the Internet for whatever value that has? One nice thing about IPv6 is your local client can continually change their address if they so want (and this is actually a common feature) to disrupt tracking. Sure you have the same prefix, but that's exactly the same boat you were in with IPv4 and NAT.