Responses
I don't think Historia's pregnancy was a plot hole. Wasn't it explained that the reason Historia got pregnant was so she wouldn't be made into a titan and used? Her pregnancy was to buy her time while Eren tried to fix things/find a different solution. I think Historia just lost her importance the moment she became queen. Like, we had Zeke with Royal blood and he was an important figure that Eren wanted to manipulate so Historia just became unimportant at that point
*SPOILERS*
I really don't like this ending. For me there's a lot of plot holes. What about Historia pregnancy? Isayama showed this like it should be something important and there're a lot of similars to Ymir pregnancy but then it's just some random topic? About Eren and Mikasa, I don't care who he loves (it's not romance manga) but this topic should be show in better way, It was too suddenly and in my opinion doesn't make any sense. I'm not saying it's a bad ending but average. From the beginning we get secrets (which make sense), suspense and a lot of emotions but this ending dosen't feel that way. It feels rushed and lacking.