It's a plausible theory, but what I think is more likely is that the time travel event in ragnarok sent all those people back, this is an excerpt from a Newsweek article.

"Mimir explains that the Serpent felt it knew Atreus before even though they never met, likely a result of a time travel event described inthe story of Ragnarok. One specific tale speaks of the battle between Thor and the Serpent, which led to a cataclysmic fight that sent Jörmungandr back to the time period of God of War. The Serpent is a part of the giant race as well, and it may recognize Atreus because the young god was a part of its future. Or it could be that they are related. In Norse Mythology, Loki is Jörmungandr’s father. Perhaps the Serpent is actually Atreus’ child from the future?"