The reveal that Atreus is actually Loki will have significant implications on the story of God of War Ragnarök, with the Nordic apocalypse and a war with Asgard on the horizon. Atreus' desire to learn more about who Loki is will undoubtedly interfere with his mission to prevent Ragnarok. He will assuredly be right in the middle of the events that bring its arrival, whether it's intentional or accidental.
The world finally got its first glimpse of God of War Ragnarök in PlayStation's latest showcase and the trailer featured some information regarding the story. In an effort to prevent Ragnarok, Atreus and Kratos search for Tyr in the hopes that he can help them. And while the trailer does show the two finding Tyr, it does raise the question of whether or not it's actually Tyr or possibly Odin playing some sort of trick, which could directly lead to the idea that Atreus will inadvertently cause Ragnarok.
In Norse mythology, Loki is responsible for causing Ragnarok to happen. And this was already teased at the end of God of War, with the arrival of Fimbulwinter and the revelation that Atreus is actually the Norse trickster god, Loki. So it's not exactly going to be a surprise if Atreus causes Ragnarok at some point in the game's story. But with Atreus and Kratos on a mission to stop Ragnarok from happening, the question will be how it all unfolds and whether or not it will be an accident, or if Atreus will bring about the events of Ragnarok on purpose.
God of War's Atreus Could Intentionally Cause Ragnarok
Going back to the prophetic wall foretelling Atreus' story at the end of God of War, it does show what appears to be the death of Kratos with Atreus kneeling over his body. With a potential war with Asgard and an inevitable showdown with Odin on the way, it's not out of the realm of possibility that Atreus could alter his objective and deliberately cause Ragnarok to happen following the death of his father. This would also present a really interesting gameplay possibility in having Atreus become the playable character at the end of the game, maybe even avenging Kratos in a final fight against Thor.
It has already been confirmed that God of War Ragnarok is the series' final entry in the Norse saga, so there's probably going to be quite a bit going on in this game. Thor and Freya have a score to settle with Kratos carrying over from the last game and Odin will certainly play a major role in what happens. However, this is still Atreus' story and Loki's traditional role in Norse mythology is almost guaranteed to put him right at the heart of God of War Ragnarök's most pivotal moments.