I don't know if this is the case, but if these images were released to press & public as part of a media resource pack with a permissive license used to market the movie (which I believe is commonly done in this industry), I'd have a hard time empathizing with the viewpoint that Midjourney is doing something wicked by including it in their training data.
You are right, the regurgitation was indeed produced by the studio for promotional purposes. But notice how the image is rendered at the link: with credit and copyright. And specifically, for promotional purposes. And while I don't presume to know the specifics of the licensing of that image, I wouldn't either assume that this use is licensed. Especially without copyright and credit.