What an awesome chapter...
It was great to see mikasa again. Her new haircut fits her so well. But the new uniform...it reminds me of an astronaut uniform? Am I the only one who thinks that?XD
But well, I think the way mikasa talked with eren revealed one thing: he made something by his own, and that wasn't supposed to happen. And we can even say that by the way she looked at him and the way he looked back. This reminds me of when isayama said that, at some point, EMA would follow different paths and that eren and armin wouldn't agree with each other and wouldn't be best childhood friends forever (or something similar, but you got the point :p). What I think is that armin(and hange) were the ones who made up all the plan and they had one way this plan should be followed. But eren, with is mind depressed and conflicted with all the memories he got from is father, had a lot of reflection and decided to do things on his own at some point, which made him and armin to get on discordance. Then, mikasa appears because, you know, mikasa loves that two boys, but eren is too problematic XD and she feels the need and responsability of helping and taking care of him but she also understands armin.
When eren asked falco to send a letter to his "family", he was probably calling for help or something like that. He sent a letter to SC to maybe explain how things were going or blah blah. But like, I believe some people went to help him, but others may be a little apprehensive. Eren is a different person now and not everyone may agree with what he decides? It is not like they don't like him anymore, it's just that...he changed lot. And it could be a little "too much" for some of them. And the fact that he went in disagreement with armin doesn't mean they don't care about each other anymore, it's just that they have different thoughts about what should be done. I don't know, it's just what I think.
If eren and armin really wento into disagreement, mikasa is in that position which requires a lot of her. She is the neutral point and damn, she loves those two boys from the bottom of her heart. She wants the best for both of them, she wants them to be ok, and this situation is not the best. That's why I can see the sadness on her face talking to eren. But he knows not everyone is like mikasa, not everyone will welcome him in a normal way.
I don't know, this is all so confusing. It seems like things are falling apart, but at the same time, they are coming together. But well, nothing comes together if they don't fall first....