WMI is partially encrypted, but IIRC it's just the authentication related details, the queries and responses are plain text. In most cases people do not consider things like the cpu load of a given server to be sensitive information.
NCM is using telnet or SSH, depending on how you set up your connection profile. Obviously telnet is plain text and ssh is encrypted.
That's what I wanted to know, if the authentication was encrypted. I wasn't thinking clearly about NCM... I use ssh, so it's encrypted. Thanks for the answer!