No one is talking about the critical change they made to the magic system. In the books, the problem with The Dragon is he can use magic, but the magic men can access has been tainted and blah blah blah. The takeaway is that women can still safely use magic, and keep on restraining men who can so they don't destroy the world.

This could have been done in such a way that would not only have opened the possibility for a woman to be the Dragon, but would have made it just as hard to determine not just who the Dragon was, but would bring in a test to determine if every magic user had the potential to be the Dragon, both men and women, let alone trans magic users. But instead, they insist that maybe this woman could be the Dragon, then portray everything else like it was in the book, leading to the likely conclusion that the Dragon will still be a man. And if the Dragon is still going to be a man, for very consistent in-world reasons which would also make sense for the characters, why pretend it was going to be anything different? If you have a problem with The Dragon having to be a man, wouldn't it be more frustrating for the Dragon to not have to be a man and it ends up being a man, anyway?

I have a number of other criticisms - oddly weakening characters, distorting their motivations for no obvious reasons, etc. - but this is the only one I saw as actually world-breaking.