The MCU will soon be starting its foray into the world of TV series on Disney+ with three of its most exciting shows lined up for 2021- WandaVision, Loki, and The Falcon and The Winter Soldier. While we have seen teasers and trailers, in typical MCU fashion, they don't really tell you anything about the shows. 

Source: UFW

In the next few paragraphs, we will be diving into the plausible theories for these shows and see where they take the MCU. 

We'll start off with The Falcon and The Winter Soldier. This will be a direct continuation of the story following Avengers: Endgame

Source: Den of Geek

Cap might have given Sam his shield and asked him to do the job, if the comics and set photos are to be believed, the US government will not accepting Sam Wilson as the new Captain America. This could also be MCU's way of integrating it's overarching mythology with that of the ground reality of the USA. 

We know from set photos and the trailer that the US government will be introducing a Captain America of their own, possibly John Walker or as we know him from the comics- U.S. Agent. Walker is sort of an anti-Steve Rogers, with a set of ideas that he believes are better suited to the generation he is in. 

Source: Movieweb

The show basically promises to be the 'war for the shield'. Speaking to Screenrant, Anthony Mackie had said that he would still be Falcon going into the series. So, we'll probably get to see him earn the shield, so to speak. Also with Zemo getting reintroduced into the story, it will be interesting to see what lies in store for The Winter Soldier. 

Source: MCU Exchange

The Loki series on the other hand, promises to be a funfest. After escaping with the space stone, it appears that Loki could be pursued by 2012 Thanos. That being said, 2012's Loki is an out and out bad guy and not the anti-hero, the Thor movies turned him to be. 

Source: Variety

The series will have 6 episodes and some fans believe that it will tie into Taika Waititi's Thor: Love and Thunder. An alternate timeline also means that a lot of characters we have seen die throughout the Infinity Saga might make cameos, if not comebacks. 

Source: Indian Express

Some other fans have also suggested that the God of Mischief wielding the space stone means that there would be multiple versions of the demigod, all appearing at some point on the show. And given that MCU Phase IV will be exploring a lot of outer world characters, this would be a perfect gateway to introduce those stories. 

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And now, we talk about WandaVision, possibly the most ambitious superhero TV show. We already know that it is going to connect to Dr. Strange In The Multiverse of Madness. So, I think, it's fair to say that the show will explore more of the Scarlet Witch's powers and one of them could be possibly poking at wormholes to other univserses. 

Source: The Indian Express

Some fan would like for Vision to return and a multiverse would be a great way of getting there. Others believe that the weird trailer with the 60s/70s background could be a part of Vision's dream. We know, he's dead but maybe Shuri did separate a part of his consciousness. 

Or going back to the original theory, Wanda Maximoff could just be creating pocket dimensions of her own and jumping through them to somehow deal with her loss. This will have consequences that we will see later in the show and most likely extended to Dr. Strange film. 

Source: YouTube

However, this could also be Marvel's secret key to introducing mutants in the MCU. For the uninitiated, in the comics, Scarlet Witch and Quicksilver are siblings, with Magneto as a parent. 

WandaVision could introduce Fox's X-Men to the MCU, which would save the time and money needed to reboot the characters and reestablish the universe. 

Source: Vulture

Fact of the matter is that these are all speculations and unfortunately these are all we have as of right now. When the shows release, we'll obviously be more aware of where the MCU is going but as of right now, it appears that Marvel is getting creative with its storytelling, adding a pinch of reality to its world, while simultaneously expanding its more other worldly adventures.