The fifth installment of What If...?, which drew inspiration from the Marvel Zombies comic series, revolves around the Avengers becoming zombies which resulted in a global zombie apocalypse. The episode was received well and fans have been wondering if the zombie storyline will just be a one-shot within the series or perhaps it will be integrated into live-action.
According to Mark Millar's recent newsletter (via CBR), a Marvel Zombies live-action project might actually be in the works. After sharing the origin story of the comic series and its success that resulted in multiple issues, toys, and an episode of What If...?, he shared in the end, "...but also (if my sources are correct) a little live-action Marvel Zombies further down the line, but you never heard that from me." He didn't mention though if it will be a feature film or a television series.
It should be noted that Marvel Studios hasn't made any confirmation yet so you have to take this with a grain of salt. It is fascinating that there is now interest in adapting the popular comic series in a live-action format. There is a rise in the zombie genre on film and television lately so that might be the reason why they are developing it (if the rumor is true). Plus, the What If...? episode was received well so fans are now at least more welcoming on seeing their favorite heroes as zombies.
Back in 2017, Free Fire director Ben Wheatley expressed his interest in directing a Marvel Zombies movie. In an interview with Little White Lies, he said, "I don’t really know how those things work. Marvel Zombies hasn’t been done which is what I’m interested in. Maybe that’s a bit too niche. Marvel’s interesting in that it’s kind of a hybrid of cinema and television. A very, very expensive TV show that you buy a pass for every three months."
Again, this is all just a rumor so this may or may not be true at all. Marvel Studios has a lot of projects on their hands at the moment so, if it is true that they are actually developing it, it might take years before it comes to fruition.