Adding a new item should cause the dependency graph recalculation.

For example, a new job might have a trigger setting to begin with,
or it might resolve a reference that was previously failing (for
example, 'up' job referring to 'down' job and the 'down' job is newly
created.)

core/src/main/java/hudson/model/ItemGroupMixIn.java

@@ -270,6 +270,7 @@ public abstract class ItemGroupMixIn {
         }
         item.save();
         add(item);
+        Jenkins.getInstance().rebuildDependencyGraph();
 
         if (notify)
             ItemListener.fireOnCreated(item);