Philippe, the patch is not for the MediaWiki software but for the configuration of Wikimedia wikis (it's in the operations/mediawiki-config repository on Gerrit).
It has been merged and deployed on the production cluster. The user right has been added to the global staff user group, and it has already been used to protect the MediaWiki:Common.js page on the German Wikipedia so that no one can edit it except Wikimedia Foundation employees.
Wikimedia Foundation is using this user right to actively fight its community of volunteers.
This is something I cannot and will not support.
Tomasz