The Matrix 4 started filming, and questions as to why Neo is alive and why Laurence Fishburne was not cast have already been answered in the canon video game The Matrix Online, which takes places immediately after the last Matrix movie

Of course take this with a grain of salt. The Wachowskis could choose that The Matrix Online isn't canon after all. But, at the time they were very adamant that it was canon and they even wrote some of the story.Why is Neo alive? One of the first major community quests in The Matrix Online was that code fragments of Neo's residual self image (RSI) we're scattered throughout The Matrix. Machines, Humans and the Merovingian factions all scrambled to collect these fragments. After a while Neo's RSI was reconstructed from the fragments. While not exactly human Neo, his RSI lived on as a program in The Matrix. My guess is that in The Matrix 4 Neo's RSI will be a program in The Matrix that humans seek out similar to The Oracle in the previous movies.Why wasn't Laurence Fishburne cast? Simply put, he's dead. Morpheus was assassinated. It was a very long story quest where humans blamed The Machines for breaking the truce and assassinating him. The war started up again between the humans and machines due to this. Eventually, it was found out that the assassin was actually a rogue program hired by the Merovingian (who ended up becoming a raid boss) and the truce between the machines and humans started once again.edit: I'm underselling the story with these short paragraphs. The story was very verbose and detailed. Every patch with The Matrix Online had a story written by professional authors. It included short stories, comics and cinematics. It's a shame that Sony took down the official story website, but you can find some of it here: https://ift.tt/2uubPYr 2: Found a pdf where someone compiled all the patch notes which has the story elements, if you really want to see how far the rabbit hole goes: https://ift.tt/2vShKqC via /r/movies https://ift.tt/39aW9rQ