I would like to see an option in the configuration files to fully remove product and version information from the server's protocol. It is part of my security concept to NOT show anything like that to outside users.
hiding the version provides no additional security. The current behavior was decided upon by consent on the samba-technical mailing list. However if you want to do this, see smbd/sesssetup.c:add_signature() and make sure to set the 'server string' appropriately in smb.conf.