While Stephen McFeely (Avengers: Endgame) and Michael Waldron (Loki) are the only credited writers on Avengers: Doomsday, the Writers Guild of America website has been updated with the credits for "Additional Literary Material."
Before we get to that, it's worth noting that Waldron's credit has been changed from "&" to "and." That may seem like a stylistic choice, but in reality, it means he was only responsible for an earlier version of Avengers: Doomsday's script and that he didn't write the current version with McFeely.
Back to "Additional Literary Material," and that's a credit which acknowledges writers who contributed to a script or project, but whose work did not meet the strict WGA minimum percentage threshold required to receive an official on-screen writing credit.
In the case of Avengers: Doomsday, McFeely and Waldron are named, as are Eric Pearson (Thunderbolts*), Chris McKenna and Erik Sommers (Spider-Man: Brand New Day), Jeff Loveness (Ant-Man and The Wasp), and Andrew Lanham and Destin Daniel Cretton (Shang-Chi and the Legend of the Ten Rings).
Pearson is frequently enlisted by Marvel Studios to help a script connect to the wider MCU, and has previously contributed to the likes of The Fantastic Four: First Steps and Black Widow. Loveness, meanwhile, was tasked with writing Avengers: Doomsday's predecessor, Avengers: The Kang Dynasty.
While Cretton's involvement has led to Spider-Man speculation, the fact that Lanham, who wrote Shang-Chi and the Legend of the Ten Rings, was also involved suggests they might have helped out with Shang-Chi's arc, in particular.
Here's where we get into spoilers, though. The rumours were true: Ryan Reynolds and Hugh Jackman are officially credited with "Additional Literary Material," confirming their respective returns as Deadpool and Wolverine. That's one of the movie's best-kept secrets, but this WGA listing has made it official.
Based on previous reports, the duo will appear in Avengers: Doomsday's opening sequence, with Deadpool also involved in the battle with the Sentinels at the X-Mansion. As for Wolverine, he's expected to have a much larger part to play in Avengers: Secret Wars.
In Avengers: Doomsday, beloved heroes from three distinct universes will be set on a deadly collision course and face an existential threat unlike anything they’ve ever encountered.
Avengers: Doomsday stars Chris Evans, Chris Hemsworth, Anthony Mackie, Winston Duke, Tom Hiddleston, Sebastian Stan, Letitia Wright, Paul Rudd, and Robert Downey Jr. Wyatt Russell, Simu Liu, Tenoch Huerta Mejia, Mabel Cadena, Florence Pugh, Danny Ramirez, David Harbour, Hannah John-Kamen, Lewis Pullman, India Rose Hemsworth, and Wesley Holloway all make their Avengers franchise debuts.
The Fantastic Four: First Steps leads Pedro Pascal, Vanessa Kirby, Ebon Moss-Bachrach, and Joseph Quinn, joined by X-Men franchise stars Kelsey Grammer, Patrick Stewart, Ian McKellen, Alan Cumming, Rebecca Romijn, and James Marsden, plus Deadpool & Wolverine star Channing Tatum.
The Russo Brothers direct Avengers: Doomsday and Avengers: Secret Wars from a screenplay by Stephen McFeely, with whom they previously collaborated on the Avengers and Captain America franchises. Loki and Doctor Strange in the Multiverse of Madness writer Michael Waldron has also been enlisted to refine the story, alongside Spider-Man: Brand New Day's Chris McKenna and Erik Sommers.
Avengers: Doomsday is set to be released on December 18.