My major complain regarding this Eren reveal is that Isayama didn't think it through.

Isayama clearly meant to make it like that since quite a few chapters back but he didn't think how it would affect the past chapters.

All he had to do is to label Eren's action as mask and façade and soon every Eren interaction / lines which were not POV become blatant lies and a mask put on by him.

Also we know that making his friends hero took precedence over killing all of humanity because it is how it happened (Even if Eren wanted to do both). But we were led to believe that killing all of humanity was his only goal. So many lines like "I keep moving forward until all of my enemies are destroyed" feel weightless now.

Hence if Isayama wanted to pull this off then he should have thought it through. He put too much focus on Eren killing all of the humanity outside wall, Eren achieving freedom etc. while his main goal was to make his friends as savior of humanity before all of this. Now Eren's character feels a bit hollow and rushed.

This was not something completely out of the blue as people would expect Eren to protect his friends, but the way it was done is clearly a bad writing that ruined the past lines and character development of Eren and hence make it seem as more of a retcon than a consistent character development.