For 3,000 years thou shalt wander over this earth, without a companion and without being able to talk with anyone. Alone and without anybody by thy side, thou shalt wander through diverse countries, O wretch, thou shalt have no place in the midst of men. The stench of pus and blood shall emanate from thee, and inaccessible forests and dreary moors shall be thy abode! Thou shalt wander over the Earth, O thou of sinful soul, with the weight of all diseases on thee.
If the three thousand years are over, then the curse of Krishna is also over. Krishna cursed Ashwathama for three thousand years so you need to find out how many years has it been since the Kurukshetra War was over till now and if the answer is 3,000 years more more than that, that means Ashwathama is no longer cursed but if the answer is less than 3,000 years, that means Ashwathama's curse is still in effect.
Also, if you recite Mahabharata or hear the Mahabharat being recited, you become cleansed of every sin.
That learned man who recites this history of sacred days in the midst of a listening auditory becomes cleansed of every sin, conquers Heaven, and attains to the status of Brahma. Of that man who listens with rapt attention to the recitation of the whole of this Veda composed by (the Island-born) Krishna, a million sins, numbering such grave ones as Brahmanicide and the rest, are washed off. The Pitris of that man who recites even a small portion of this history at a Sraddha, obtain inexhaustible food and drink. The sins that one commits during the day by one’s senses or the mind are all washed off before evening by reciting a portion of the Mahabharata. Whatever sins a Brahmana may commit at night in the midst of women are all washed off before dawn by reciting a portion of the Mahabharata.
So if Ashwathama recites Mahabharata, his sins are washed.
Ashwathama is also the next Vyasa in the 29th mahayuga.
In the next Dwápara, Drauńi (the son of Drońa) will be the Vyása, when my son, the Muni Krishńa Dwaipáyana, who is the actual Vyása, shall cease to be (in that character)
Parasara, the father of Krishna Dwaipayana Vyasa is describing Vishnu Purana so when he said Vyasa, he said his son.
Ashwathama will also be the next Saptarishi in Savarni Manvantara
In the period in which Sávarńi shall be the Manu, the classes of the gods will be Sutapas, Amitábhas, and Mukhyas; twenty-one of each. The seven Rishis will be Díptimat, Gálava, Ráma, Kripa, Drauńi; my son Vyása will be the sixth, and the seventh will be Rishyasringa
Not all Brahmarishi are Saptarishi but all Saptarishi class members are Brahmarishi and Ashwathama is future Saptarishi in Savarni Manvantara and also future Vyasa