As per this answer, it is said that the Pandavas, Karna and Duryodhana went to heaven or hell.
What about others like Abhimanyu, Ghatotkacha? Were they reborn?
Actually the stay in heaven is too brief. After that Karna joined Surya. Bhima was one of the Maruts. Bhishma was one of the Vasus. Drona a part of Brihaspati. Twins joined Ashwinis. Arjuna attained Vaikunta. Abhimanyu joined Soma (Chandra dev). Gandhari, Dhritarashtra etc. became Gandharvas. All are liberated.
Bhishma of mighty energy and great effulgence attained to the status of the Vasus. Eight Vasus, O chief of Bharata’s race, are now seen. Drona entered into Brihaspati, that foremost one of Angirasa’s descendants. Hridika’s son Kritavarma entered the Maruts. Pradyumna entered Sanatkumara whence he had issued. Dhritarashtra obtained the regions, so difficult of acquisition, that belong to the Lord of treasures. The famous Gandhari obtained the same regions with her husband Dhritarashtra. With his two wives, Pandu proceeded to the abode of the great Indra. Both Virata and Drupada, the king Dhrishtaketu, as also Nishatha, Akrura, Samva, Bhanukampa, and Viduratha, and Bhurishrava and Sala and king Bhuri, and Kansa, and Ugrasena, and Vasudeva, and Uttara, that foremost of men, with his brother Sankha—all these foremost of persons entered the deities. Soma’s son of great prowess, named Varchas of mighty energy, became Abhimanyu, the son of Phalguna, that lion among men. Having fought, agreeably to Kshatriya practices, with bravery such as none else had ever been able to show, that mighty-armed and righteous-souled being entered Soma. Slain on the field of battle, O foremost of men, Karna entered Surya. Shakuni obtained absorption into Dwapara, and Dhrishtadyumna into the deity of fire. The sons of Dhritarashtra were all Rakshasas of fierce might. Sanctified by death caused by weapons, those high-souled beings of prosperity all succeeded in attaining to Heaven. Both Kshattri and king Yudhishthira entered into the god of Righteousness