A Polygon analysis of Spider-Man: Brand New Day argues the film's most significant clue about the upcoming X-Men storyline in the Marvel Cinematic Universe is not Sadie Sink's confirmed casting as Jean Grey, but the introduction of "power inhibitors" as a plot device. This detail matters because it appears to lay groundwork for the mutant-suppressing collars long associated with X-Men lore, suggesting Marvel is quietly building infrastructure for anti-mutant persecution storylines ahead of the mutants' full MCU debut.

In the film, Bruce Banner wears a device suppressing the Hulk, and after Peter Parker's powers intensify, the pair discuss creating a universal inhibitor capable of suppressing any superpowered individual, repeatedly using the word "mutation" in the process. Spider-Man later uses the finished device against Jean Grey, prompting Banner and Jean to raise ethical questions about suppressing part of someone's identity. The article notes the inhibitor's neck placement echoes the mutant inhibitor collars seen in X-Men comics, cartoons and films such as Deadpool 2 and X-Men: Days of Future Past, and observes the irony that Banner and Parker—traditionally allies of mutants—may have inadvertently created a powerful anti-mutant weapon. Spider-Man: Brand New Day is now in cinemas.