If NVC contacted the petitioner/applicant to request the documents more than one year ago, the principal benefciary may need to file I-824 for the derivative (spouse and child) to use following to join benefits or just file I-130 for them.
Normally, NVC close the immigrant case after one year from the date when NVC requested the documents if you do not file DS 260. Your friend can contact NVC to see whether the case is still open for his spouse and kid to follow to join. If no, just wait for the I-130 approval. Your friend do not need to file I-824 (save some money) becuase he has filed I-130. Not need to withdraw the I-130.