After 139. There may be an alternative ending. Erens stuck in a time loop or there's 2 different timeline. We might get another chapter or different Anime ending.
-Zero No Requim
ending, Eren died. Mikasa lived.
-Akatsuki no requim
The other one Eren will live, Mikasa will die

My interpretation onto the devil and girl picture https://twitter.com/imalwayzsleepy/status/1380399391500996610?s=19

If we do get another ending in the anime or manga. The devil and girl picture would make way more sense in my opinion.

I also put a bunch of songs and anime opening/scenes in this post early on to further explain my theory. Ignore my favorite ship. I just thought it would fit thematically into the story for that one song. Maybe it could be an eremika baby. I don't know lol https://twitter.com/imalwayzsleepy/status/1380356989075644421?s=19

Proof akatsuki no requim is about Mikasa death and that there might be an alternative ending for either anime or maybe later in the future Manga.
A scarf is around the tomb stone.
Basically in this one he would succeed with the rumbling, but Mikasa gets killed along the process

More proof that anime and manga may might be alternative timelines colliding into Erens head as well.
I noticed that some of the shards show birds flying bird but manga Eren eyes have never had birds in the Manga

Finally the birds from the memory shards are always placed in the position as they are in the eyes from the anime. It's possible ending might not change but the possibility is still there cause of how different Erens dream of season 1 and it is from the manga.

If my theory ends up being right that the anime is an alternative timelime of aot. I'm pretty certain that the baby daddy information will be revealed and it didn't for a reason. I kind have an idea of who it could be.
Some shippers will be angry.

139 never specifically stated the the farmer was the father. Historia wasn't even married to the farmer before the rumbling and during. Only married the Farmer after the rumbling stopped. She was supporting the yeagerist group. I'll leave it at that as a clue of who I suspect.

More proof the anime may be an alternative timeline compared to the manga. All Ovas are canon in the anime canon, so is the Krista missing one.
Blue butterfly=symbolic of change in time, alternative timeline, or universe. Shown in Mikasas Ova which is anime canon. Steins gate ex.

Steins gate is an anime where the main protagonist travels through different timelines and tries to save 2 girls he cares for very deep but in each one he travels to 1 dies and so ends up traveling timelines until he can save both. It's pretty good. I recommend it