Under https://phabricator.wikimedia.org/applications/view/PhabricatorManiphestApplication/ we have Can Edit Task Policies: Custom Policy set to numerous acl* projects, Security, etc etc.
This setting has been removed in upstream in https://secure.phabricator.com/T10003.
Our docs for Phab admins creating Spaces currently say
add "Allow members of acl*groupname_policy_admins" to Phabricator's global custom "Can Edit Task Policies" setting. This is required to display the "Visible To" and "Editable By" fields (and hence the Spaces dropdown for members of that Space) in the task creation form.
Hence find out how this upstream change will affect our Spaces workflow, and if it somehow does not, @Aklapper to 'only' update our on-wiki Spaces documentation.