only in patch2:
unchanged:
--- a/core/modules/views_ui/js/views-admin.js
+++ b/core/modules/views_ui/js/views-admin.js
@@ -276,6 +276,8 @@
 
       var group = this.$controlGroup.val();
 
+      // Search through the search texts in the form for matching text.
+      var activeViews = 0;
       this.options.forEach(function (option) {
         function hasWord(word) {
           return option.searchText.indexOf(word) !== -1;
@@ -291,9 +293,15 @@
         }
 
         option.$div.toggle(found);
+        activeViews += found;
       });
 
       $(event.target).trigger('dialogContentResize');
+
+      Drupal.announce(
+        Drupal.formatPlural(activeViews, '1 option is available in the modified list.', '@count options are available in the modified list.')
+      );
+
     }
   });