Lol, seriously, guys? I will explain it to you:
1) Pieck might have told Eren her true feelings regarding their situation but she didn't betray Marley or, more correctly and personally, her comrades;
2) Yelena explained Zeke's insane plan to the characters, Jean called it bullshit and Armin once again used his master manipulator persona to make Yelena believe he actually got touched by her and Zeke's crazy ideas;
3) based horse god Jean tried to explain to the slower or doubtful readers that Eren has a plan that involves making Zeke believe him and his friends to hate him;
4) Magath is the one true Marleyan Daddy.