The first of those trailers, featuring the return of Chris Evans as Steve Rogers, has already leaked online, initially in grainy, low-resolution style. The poor quality of that trailer — which Disney has apparently been working diligently to scrub from the internet — has led to questions about its authenticity. Some viewers have expressed disappointment about how little it shows, while others have alleged that it's the work of generative AI, not the hit-making Russo brothers and Marvel Studios.

New, higher resolution uploads of the first Avengers: Doomsday trailer certainly lend weight to its legitimacy. Additionally, multiple Marvel fans have recreated the Avengers: Doomsday teaser through generative AI shot for shot — to illustrate just how terrible AI-generated trailers actually look. (You can go to YouTube and find dozens of fake, gen-AI Avengers trailers that imagine what Robert Downey Jr.'s Doctor Doom might look like.)