The plot of this episode is heavily inspired by the Marvel Comics "Age of Ultron" storyline. However, elements from various MCU films are also highlighted in this episode.
This story takes place in the Earth-29929 version of the Marvel Universe.
Natasha does the superhero pose a number of times that Yelena made fun of in the movie, Black Widow (2021).
Ultron being able to easily kill Thanos implied Vison could have done so in Infinity War if Corvus Glaive hadn't injured him.
It's implied Ultron killed Wanda and Pietro in this timeline; which is why the Avengers couldn't steal the cradle and create Vision.