In the latest chapter we have seen Griesha sees his son Zeke as a grown man with a bread, in what looked to him like a dream, when Zeke and Eren were seeing the memories through the paths.
Previously, we have seen Eren Kruger talks to Griesha about Armin and Mikasa, many years before they were even born, and said: who knows whose memories these are?. Could it be also someone, most probably Eren Yeager, traveled back in time through the paths and talked to Kruger about Armin and Mikasa?
Does this explains Eren's dream in the first episode, even though he had no titan by then?
Finally, does this explain the following theory:
First episode is titled: To you, 2000 years from now. We know that Yimir Fritz took the titan power from the devil and was cursed with living max 13 years after that. Then, 144 kings took the founding titan one after another, with each living maximum of 13 years. Until Karl Fritz the 145th king who took the founding titan at the year 743 and moved to Paradise Island. At year 845 Eren took the founding titan, along with the attacking titan from his father. Now we calculate how many years from Yimir Fritz until Eren getting the founding titan: 13 + (13x144) +(845-743) = 1987 years. Which are missing only 13 years to complete 2000 years which are the years for Eren to live since he got the founding titan. This theory assumes that all kings lived their full 13 years, which is very possible, since the weapons that kill titans were invented in the Paradise Island after the 145th King. Now the theory is: Eren also can travel back in time through the paths, while touching someone with royal blood, and tell a message to Yimir Fritz (2000 years from now).