people keep saying this chapter "confirms" the time loop theory but I don't know such thing, could you briefly explain what it is? and how this chapter justifies it?
Time travel theories go back to chapter 1 when Eren dreams of the girl in a scarf who says “See you later, Eren.” It looks like Mikasa from future training days but her face is deliberately obscured.
Eren’s premonition or vision of the future opens a few possibilities: 1. Eren is clairvoyant or 2. Eren has lived this life before and memories are leaking through in his dream state. Thus the time loop theories.
The chapter 1 title, “To You in 2000 Years”, added fuel to this because it could be read as indicating that the canon events had an impact on a future people. It’s as though the entire manga was set up as a cautionary letter. Now that we have The Grisha Files, it seems just as likely that the “To You in 2000 Years” is talking about the people in the present, those who are impacted by Ymir’s deal with the devil 2000 years previous.
This chapter added a new element. Kruger apparently mentions Armin and Mikasa by name. He and Grisha both seem confused by this. That Kruger knows their names means that either he’s read about them in a historical document, or he too is plagued with premonitions.
I’ve seen some theories that the “See you later, Eren” in chapter one is referring to Eren Kruger, and not Eren Jaeger. I’ve seen speculation that both Erens are different versions of the same person in the loop. I think it’s all very interesting but I don’t have strong feelings about any of them.
I’d be surprised and disappointed if this manga has a time travel element. I don’t think this chapter confirms anything. It just adds a new and interesting mystery.