It remains to be seen now "Madame Web" will tie into the MCU or if it will at all. As part of the Spiderman universe, this film could simply be a branch off of that part of the Marvel universe and remain there.
Starring Dakota Johnson, Madame Webb is the story of a paramadic whose critical life altering accident gives here psychic powers. The film also stars Sydney Sweeney. The film is being billed as a sort of "suspense thriller."
Sweeney eventually becomes Spider Woman in the Marvel comics and this film is likely to explore how she obtained those powers.
Is this a film that needs to be made? The MCU is bleeding but the one successful property still churning out big dollar box-office success is Spiderman. The last film, Spider-Man: Across the Universe was a huge hit for Marvel.
It's hard to imagine this film hitting a similar stride within the universe and it could simply become a catapult for a future Spider-Woman featured film or a collaborative film with Spider-Man.
Whether this film is actually needed or not needed isn't really a question anymore. It's on it's way and will be part of the MCU. Again, to what degree of integration with the main MCU storylines isn't 100% known.
On the other hand, this film could present Disney with another female superhero lead that will attract younger viewers in the tween to young adult demographic.