When the first MCU Disney+ series were announced, Marvel fans had questions about how essential these shows would be to understanding new MCU movies. The interconnected nature of the Marvel Cinematic Universe has often placed a certain amount of pressure on audiences to keep up to date with the entire franchise, as any one entry may reference any other. While there was clearly excitement to see MCU storytelling extend to television in a form that was more integrated with the movies than had been seen before, there were also fears that fans not following the streaming series would be out of the loop when watching new MCU movies. The Marvels puts that excitement and those fears to the test, leaning heavily on Marvel's Disney+ shows.
Source:https://www.cbr.com/the-marvels-wandavision-ms-marvel-essential-viewing/