We all know the MCU is inevitably going to collapse, right? It’s a shared superhero continuity, an attempt to force an ever-expanding number of stories into the straitjacket of continuity nitpickery. It is not only deliberately encouraging the paranoid reading style and gossip about imaginary people, it wants us to see Guardians of the Galaxy and Daredevil as two windows into the same world.
So of course, sooner or later, it will do what the comics always do, and implode. The need for ever-more obscure references in order to build ever-more elaborate conspiracies for viewers to unravel, combined with the unrestrained growth of constantly adding new characters and new media–so far, in order to fully follow the MCU, it is necessary to watch two network television shows, a web-series, and five film series–and those numbers are growing allm the time.
Now of course it’s possible to follow and enjoy an Avengers movie without knowing what’s going on in Agents of SHIELD (says the person who hasn’t watched any Marvel TV shows). But remember, it is the nature of a conspiracy theory to grow more convoluted and complex with time, and a shared continuity is essentially a conspiracy theory about a group of fictional works. Right now, the MCU films spend relatively little of their time laying clues for future films or paying off clues dropped in other series–but that amount is growing.
There is a particular minor subplot in Age of Ultron (if you have seen the film, you know which I mean) which serves no purpose except to bring Age of Ultron‘s own story to a screeching halt so that it can spend a few minutes congratulating us nerds who recognized how Captain America, Thor 2, and Guardians of the Galaxy were building toward Avengers 3. (To his credit, Whedon apparently fought against including these scenes, and had to be forced into it by executives threatening to cut a major character-building sequence. But not too much credit; that sequence includes Black Widow suggesting that being unable to have children makes a woman a monster.)
This kind of thing is only going to keep getting worse. How long until plot threads introduced in Agent Carter get resolved in Ant-Man 3? Until we get entire films that exist solely as set-up and teaser for the next big crossover? Until the whole thing is just the same mess of conflicting reboots, alternate universes, and continuity lockouts as mainstream comics?
(Rhetorical questions, but I’ll answer anyway: No later than Avengers 4, and possibly much, much earlier.)