To add to this theory one of Mimir's tales is playing with the idea of why Odin wants Kratos and Atreus:
"Atreus: So what do you think, Mimir? What does Baldur want with us?
Mimir: Well… let’s look at what we know. Baldur is Odin’s finest tracker, bar none. If he wants you, you have to consider the possibility that Odin wants you. And as for what Odin wants, on this I have some expertise.
Atreus: What could WE have that Odin doesn’t? He’s like the king of gods!
Mimir: Of the Aesir, aye, but his reach is not unlimited. And where he cannot reach, he is preoccupied with going. He certainly tortured me enough about it over the years."
the Journal entry for the tale states:
"Mimir thinks Baldur is tracking us for Odin, who wants to go "where he cannot reach"... but WE can?"
The thing is Odin knew everything thing about our journey in GOW 2018 and what we will do and likely how to do it as was mentioned he saw visions of Kratos and Atreus in Ragnarok during the Lost Pages of Norse myth about Groa and knew he was a God from another land. So I think Odin spying on us to get to Jotunheim is an intended misdirection by the devs, just like we were led to believe Baldur was sent to find Kratos and Atreus rather than Faye was an intended misdirection. Mimir thinks Odin is out to find Jotunheim because he thinks Odin is relying on the giants to have the knowledge of how to change his fate but Odin should already be aware that there were no giants in Jotunheim and Odin should be aware that the Ragnarok he seen is a different/altered fate from the one prophesized by giants on murals so he knows fate can be altered. Odin knew Skoll and Hati catching their prey is the kickstart for Ragnarok yet didn't kill them as pups and actually set them on their prophesized course. Just as Odin kick-started Skoll and Hati's chase early, Odin knew Baldur has to die in order to commence with Ragnarok early and he purposefully sent Balder after the Ghost of Sparda knowing he would eventually be killed. Going back to my theory, I really think Odin wants Ragnarok to happen so his world can be considered a "dead pantheon" and he would be able to reach pantheons that he wouldn't be able to normally without a Unity Stone.