The Marvel Multiverse Theories Explained: How Marvel’s Future Storylines Will Change

It is hard to imagine a Marvel universe without the characters we have grown to love since 2008, but this is the world we now live in. Phase 4 is what will decide whether Marvel will be able to carry on without some of its iconic characters. This new era in the MCU is meant to introduce new characters and rebuild a team that will face the next big catastrophe. The BIGGEST and NEWEST change has been the creation of the multiverse. Following this change are features that will dive into this complex multiverse, such as the movies Doctor Strange in the Multiverse of Madness and Spider-Man: No Way Home.
To understand this, we will have to backtrack a little bit.
The Multiverse

Let me set one thing straight: the multiverse has always existed. Yes, this makes us question what we already know from the past, but this doesn’t precisely change what we already know happens in the “Sacred Timeline”. It is a weird and abstract concept to understand but bear with me.
Loki introduces the TVA (Time Variance Authority) who oversee the harmony of the main timeline. Most of the show progresses at the headquarters of the TVA. This place is not tethered to the rules of time and place; it exists in its own realm and has its own rules because it DOES NOT progress in the normal pace of time. So, when Sylvie and Loki travel to the Citadel at the End of Time, they find themselves under similar rules. Think of this place in a dual way, where it is the end and the beginning of time. This is why when Sylvie kills He Who Remains the “Sacred Timeline” branches from the very beginning.
Like I said, this DOES NOT change what has already happened, but it will change what is to come. As the audience, we are to assume that everything coming will progress in the main timeline (I say this loosely because there really is no more main timeline, it is a matter of perspective; from ours it is) but from now on Marvel will probably have to label what universe they are on so that we don’t get confused.
Since there are many ways Marvel can proceed, I’ll keep the theories labeled.
Theory A

Marvel has teased new superheroes, such as Shang-Chi and Ms. Marvel, and in the upcoming months we are going to learn their hero trajectory (a.k.a. learning how to use their powers and defeating their first villains). We can assume these new people will be the next Avengers and overthrow Kang’s dictatorship over the multiverse. But this brings to question where they belong within the main timeline. It is easy to imagine that all these brand-new heroes will join the MCU in the post-Endgame era, but after Black Widow, their beginnings could be dated in a time before that. If the latter is the case, then it brings to question where they were when the world needed them. Which takes me to Theory B.
Theory B

These new superheroes live in their own universe. So far, we know the MCU will visit two additional universes because of Spiderman: No Way Home, but we also know that the multiverse has infinite possibilities. It could very well be that the new heroes belong to their own timeline and are part of the team in their world. While for us it is unthinkable to imagine an Avengers team without Captain America, it could be that in another timeline he never froze, got selected for the serum or even existed at all. Which is why, different superheroes from ours were born.
How Will the Multiverse Issue Be Solved?

This is an extremely loaded question that really narrows down to two answers:
- The Sacred Timeline “cuts” its branches: The main timeline returning to what we know is the cleanest move for Marvel. While it would get rid of many possibilities, it is what narrows down the story back again to a straight line and gets rid of the messiness, that is, if only Theory A is true. But if Theory B is real then “cutting off” those branches would mean that the superheroes born in other timelines would disappear. And while Marvel is all for the drama, getting rid of the new faces is bad for business.
- The multiverse remains and is regulated by the TVA: This option is what I consider the most likely. While it is messy and complicated to keep the multiverse open, it is what makes the most sense. For one thing, it would allow Marvel to keep rolling out movies and shows, but it also opens the possibility for different versions of the heroes we know to make an appearance. As for Theory A and B, keeping the timeline open would allow for inter-universe travel to help each other out in future phases.
With all this explained, there is still one last thing I want to address: I think the multiverse issue will be solved pretty quickly. One of the last installments of Phase 4 is Ant-Man and the Wasp: Quantumania which will feature Kang the Conqueror as the villain. Unless they fail to defeat him, this could be the end to the multiverse issue. And only then, Marvel would move forward and unveil all the Skrulls that have taken a place in government. I believe the next fight will be against this alien race.