Updated the changes from the previous commit.

src/Plugin/Field/FieldWidget/InlineEntityFormComplex.php

@@ -224,6 +224,20 @@ class InlineEntityFormComplex extends InlineEntityFormBase implements ContainerF
       $summary[] = $this->t('Automatically open creation form');
     }
 
+    switch ($this->getSetting('removed_reference')) {
+      case self::REMOVED_KEEP:
+        $summary[] = $this->t('Always keep unreferenced @label.', ['@label' => $labels['plural']]);
+        break;
+
+      case self::REMOVED_OPTIONAL:
+        $summary[] = $this->t('Let users decide whether to keep or delete unreferenced @label.', ['@label' => $labels['plural']]);
+        break;
+
+      case self::REMOVED_DELETE:
+        $summary[] = $this->t('Always delete unreferenced @label.', ['@label' => $labels['plural']]);
+        break;
+    }
+
     return $summary;
   }