Unless I have misunderstood what you are proposing, Nigel, I think I would prefer it if you did not change this code.
“Internal messaging with e-mails” is my default setting for all users. A number of users over the years have specifically requested that their e-mail addresses should not be disclosed and that they wish all contact to be via internal messaging, so I made it my standard approach – leaving individuals to decide whether to open up their e-mail details to others at the first contact. There are many places on my site where I have referred users to others for more details on a particular branch of the tree where I have chosen not to extend further on my database. My standard method of doing that is to say “Registered users of this website, when logged in, may contact xxxx via the site messaging service”