It didn't change anything. It just showed what eventually happened in the future. There will always be war, it was said throughout the show multiple times and in my opinion the ending is even more realistic now. Isayama just gave us a few glipses of the inevitable future events
Ofc it’s change everything, in the 139 the titan was supposed to be gone for ever, the extra change all the end
Eren may have lifted the curse of Ymir by changing eldian people's dna or sth like that? but did u see them killing the ancient era organism that was to blame for the existence of titans in the first place?
I don’t understand, isayama told that the extra was just here for more details, not change EVERYTHING,