We add noreferrer to the rel attribute of links in Kibana that contain a remote target to help prevent cross-tab abuse of the opener object, but this is only necessary when the external link is potentially untrusted. We have full control over the code deployed to the official Elastic docs (and we don't abuse opener), so these don't need to be restricted in this way.

We'll need to update EUI as well to make sure it whitelists elastic.co for its noreferrer check.