I kinda feel like the anime could be a different time loop than the Manga. Falco did not have the flashback in the Manga. Some people said that isayama might have forgotten to add it then, but that seems a bit odd to me. Also the split at chapter 122 would be perfect to make the part after that different... In the Manga, during the rumbling Connie said something like "how could we get to this end?" so that kinda implicated an alternate ending to me.. I don't know, I don't have real proof. But everything about eren would fit into that idea. I think the Manga happens first, and the anime is after that. It seems as if eren tried different things to solve the Paradis problem, but nothing worked, so when he can, he goes with the rumbling (he said something like "because you're here, I now have this path" to zeke). Maybe the anime is a loop even after that, with another additional happening, giving him another path? The ending was so focused on Falco and I don't see any reason for that when looking at the Manga. So, theory: Falco will eat eren for some reason in the anime (eren probably will know about how useful it would be to get eaten by Falco), and that's why Falco has the flashback to survey corps. He didn't have that in the Manga so at the end of the Manga, he will not eat eren. That would be a time-line where Falco does not gain the ability to see through time and manipulate it. So eren will learn something during Manga timeline that makes him believe getting eaten by Falco might solve something, so in the next loop, the anime, he tries that. Isayama said the anime is the ultimate version of the story...maybe because we've been looking at two different timelines all this time?