Spider-Man: Across the Spider-Verse features a brilliant reference to one of Spider-Man's MCU adventures, No Way Home. But as it turns out, the writers never got approval from Disney and Marvel Studios for this reference.
At one point in Across the Spider-Verse, Miles Morales (Shameik Moore) is arguing with Spider-Man 2099 (Oscar Isaac). The latter says to Miles, “Don't even get me started on Doctor Strange and that little nerd on Earth-199999.” This is a clear reference to No Way Home in which Doctor Strange (Benedict Cumberbatch) helps that universe's Peter Parker (Tom Holland) by attempting to reverse the events of Far From Home.
Speaking to Rolling Stone, Across the Spider-Verse producers Phil Lord and Christopher Miller revealed that they never got approval for this MCU Spider-Man diss. When asked about how much MCU negotiation with Kevin Feige and Co. went into that line, Miller said, “None. We did it. It’s been our policy to do what we think is interesting and best and let the lawyers and business affairs people figure out what’s possible, and so far we’ve been able to do the things that we think are good.”
The Rolling Stone interview with Lord and Miller revealed a lot about the latest Spider-Man film. In the same interview, the duo tackled the concept of superhero fatigue. Lord and Miller have been a successful filmmaking duo since they got their feature film start with Cloudy With a Chance of Meatballs. They also directed 21 Jump Street, 22 Jump Street, and The Lego Movie, and have now been involved in the uber successful Spider-Verse franchise as producers and writers.