And he who was known as the mighty Varchas, the son of Soma, became Abhimanyu of wonderful deeds, the son of Arjuna. And before his incarnation, O king, the god Soma had said these words to the celestials, 'I cannot give (part with) my son. He is dearer to me than life itself. Let this be the compact and let it be not transgressed. The destruction of the Asuras on earth is the work of the celestials, and, therefore, it is our work as well. Let this Varchas, therefore, go thither, but let him not stay there long. Nara, whose companion is Narayana, will be born as Indra's son and indeed, will be known as Arjuna, the mighty son of Pandu. This boy of mine shall be his son and become a mighty car-warrior in his boyhood. And let him, ye best of immortals, stay
on earth for sixteen years. And when he attaineth to his sixteenth year, the battle shall take place in which all who are born of your portions shall achieve the destruction of mighty warriors. But a certain encounter shall take place without both Nara and Narayana (taking any part in it). And, indeed, your portions, ye celestials, shall fight, having made that disposition of the forces which is known by the name of the Chakra-vyuha. And my son shall compel all foes to retreat before him. The boy of mighty arms having penetrated the impenetrable array, shall range within it fearlessly and send a fourth part of the hostile force, in course of half a day, unto the regions of the king of the dead. Then when numberless heroes and mighty car-warriors will return to the charge towards the close of the day, my boy of mighty arms, shall reappear before me. And he shall beget one heroic son in his line, who shall continue the almost extinct Bharata race.'
Chandra deva wanted his son Varchas to become Abhimanyu, live on earth for onyl 16 years and wanted Abhimanyu's son only to continue toe almost extinct Bharata race which is why Krishna revived Parikshit even though Ashwathama used his Brahmashira astra on Parikshit.
Hearing these words of Soma, the dwellers in heaven replied, 'So be it.' And then all together applauded and worshipped (Soma) the king of stars. This means that gods agreed to Soma.
All five upapandavas were killed by Ashwathama in night raid and Abhimanyu and Ghatotkacha died during war on 13th and 14th day of the war respectively. Bhima had a son from Valandhara, a Kashi princess who was Sarvaga, only remaining son of Bhima as he did not participate in Kurukshetra war. He became the king of Kashi, his maternal kingdom and later Sarvaga's granddaughter who is Bhima's great-granddaughter marries Abhimanyu's grandson and Arjuna's great-grandson Janamejaya and they give birth to Shatanika. Sahadeva's son Suhotra and Nakula's son Niramitra became crown princes and later kings of Madra. Yudhisthira's son Yaudheya from Devika ruled his maternal kingdom Sivi.