First of all, I think that the first reason why the ending will be better received is bc a part of the manga readers keep saying that the ending is shitty and trash, so basically anime only’s expectations aren’t high. So, when they’ll watch the episode, they’ll probably think “oh, actually this isn’t that terrible”. They also didn’t make dumb theories during several months/years so they’ll not be disappointed by their preferred ending not being animated.

Plus, the music, the animation, the va, the dialogues being changed, the emotion and a loooooot of others little things like that, will help. Let’s be honest, a good animation makes the experience feel better, the majority will enjoy it and be more touched than the people who only read the manga.

Also, a lot of them are certain that Eren will die. They’re prepared to it. The anime captured pretty well the goals of the alliance, and progressively, it became easy to understand that someone has to kill Eren.

And I wanted to say that, for me, the ending is a 7/10. It was a little rushed in the manga so, if they fix it correctly in the anime, I’m confident by saying that most of them will love it. But ofc there’ll be people to hate it, cuz we can’t satisfy all the fandom.