See: https://html.spec.whatwg.org/multipage/links.html#link-type-noreferrer

We already use:

  nofollow noopener

for links to reduce the utility of spamming a tracker (nofollow) and
prevent a link opened from a tracker from interacting with the tracker
via the opener handle. Adding noreferrer implements noopener for IE
and also prevents the referer (sic) header from being sent to the
server for the link.

So this is an incremental improvement to what we have.

I don't like loosing the referer header as that could be useful to the
destination web site. But IE won't die.

This is as easy as finding all instances of noopener and adding 
noreferrer.

IE is really dying. So skip noreferer. Opened new issue to add ugc relation (user generated 
content) that is now needd with noopener to reduce the value of links to spammers.