All of this is a bit complicated by the fact that Alfie didn’t die in “Peaky Blinders” season 4, but reappeared in seasons 5 and 6, never to mention the cancer again. He said he had been in the hospital for months following the gunshot wound, but did not mention the illness he had suffered from a “perforation” before. And while he currently has a horrifying scar from the bullet he shot in the face, he’s also not clearly ill.
While Alfie’s sudden disappearance from health problems may seem like a hole in the plot, there could be more to it than that. On the surface, it makes sense for Alfie to lie to Tommy to let the sometimes courageous friend do what has to be done in killing him. This is a popular fan theory, but it won’t explain Schiavo’s comments about the character having lung cancer.
Another theory is even more surprising. In BBC’s Podcast “Haunted by…”, director Anthony Byrne talked about Alfie’s return to season 5, and cast doubt on his place in the story. When discussing the scenes in which Tommy imagines him talking to his dead wife, Byrne said that he also sees the Alfie scene as something less than real life. “I always say it’s not real,” Byrne said. “It’s something like being somewhere else, that it’s in limbo. But things just happen to be real because you’re dealing with someone’s mental health.”
https://www.slashfilm.com/964318/tom-hardys-skin-might-just-be-peaky-blinders-biggest-mystery/ Tom Hardy’s Skin Could Be Blind Man’s Biggest Mystery