The Marvel film universe, also known simply as MCU, has only been made up of movies so far. But that will change from the phase 4, and as expected, it will be necessary to watch both movies and series if we want to understand all the events. This has been confirmed by the president of Marvel Studios.
Yes, in the past there have been series based on Marvel characters that are somehow connected to the MCU of movies, some even still exist. Agents of S.H.I.E.L.D., for example, is one of them, in addition to those of Netflix as Daredevil or Agent Carter. However, although these series take into account the events of the films for their plots (such as the invasion of the Chitauri of The avengers or the Sokovia Agreements of Civil war), movies don't really take those series into account.
In the case of productions for Disney +, it is completely different. The series that Marvel is developing for the Disney streaming platform are part of the MCU phase 4, so Kevin Feige, president of Marvel Studios, has confirmed the inevitable in an interview with Bloomberg. According to the report: if you want to understand everything in the next Marvel movies, you will probably need a Disney + subscription.
The Disney + series will tell stories related to important characters that we have already seen in the MCU, and we will probably see them again in future films, after their own series. Those stories will connect with those of some movies, even laying the groundwork for their events. For example, Scarlet witch, which will have its own series along with Vision, will be a perskey onaje in the movie Doctor Strange in the Multiverse of Madness, according to Feige, and the series of Loki somehow it will connect so much with Thor: Love & Thunder as with the second Doctor Strange movie.
Marvel has five series in development for phase 4 of the MCU, which will be released by 2022, including WandaVisionLoki Hawkeye Y The Falcon and The Winter Soldier. (Bloomberg via ComicBook)