Hi Andrew. I just discovered this safety information and I saw it was not implemented in Ultra theme so I added it to my child theme.
Wordpress default displays the version you are using. If a security hole is published and we do not update our theme hackers have information about our WordPress. If we do not hide this information we are giving facilities to those who want to access our admin panel.
Thanks for sharing this tip. For sure, on your site this is a handy little security addon. Unfortunately, on WordPress.org the theme standards are quite strict. At the moment themes aren’t allowed to remove default functionality like the sort you’ve described above. Some of the security plugins out there will offer this same header information removal as an option.