A number of error messages either just assume that administrators can always do X and have that hardcoded (e.g. undeletehistorynoadmin) or assume that if a group has right X then it also has the right to do X on the current page and just say "you should be a member of <these groups> to do X" when actually those groups can't do it either (pretty much everything using the badaccess-groups message does that).

This results in misleading error messages after T190015: Create separate user group for editing sitewide CSS/JavaScript that does not include administrators by default (and before that for any extension making non-trivial rights management changes, presumably).