@Override
  public void afterCreate(EntryEvent<String, Object> event) {
    if (!readyForEvents) {
      return;
    }
    ObjectName objectName = null;

    try {
      objectName = ObjectName.getInstance(event.getKey());
      Object newObject = event.getNewValue();
      proxyHelper.createProxy(event.getDistributedMember(), objectName, event.getRegion(),
          newObject);
    } catch (Exception e) {
      if (logger.isDebugEnabled()) {
        logger.debug("Proxy Create failed for {} with exception {}", objectName, e.getMessage(), e);
      }
    }

  }
This listener is attached to the Monitoring Region to receive any addition or deletion of MBEans

It updates the last refreshed time of proxy once it gets the update request from the Managed Node
geode-core/src/main/java/org/apache/geode/management/internal/ManagementCacheListener.java