Thor, a god from Asgard, realized that Ultron was quoting Disney films. How? That's the magic of Disney: it's everywhere! Even in Asgard! (and perhaps in Jotunheim, too)
At one point in the "Bat Blood" video, Batman notes that "Band-Aids don't fix building holes". This may come across to some people as being a bit of a weird thing to say, but this is Batman who's saying it. If anyone would know if you could fix major structural damage with Band-Aids, it would be him.
During the Infinity War Deadpool video, the Joker bets that Thanos's kill count will be 0. Considering the trope he invented, it's only appropriate that he doesn't think Thanos will be able to kill anyone off.
Why did they choose Johnny Storm as the Fantastic Four member killed in the Thanos Snap? Because bothactors were already in the MCU.
How Back to the Future Part II Should Have Started provides a rare example not lampshaded by anyone in-universe. Doc's claim that giving Marty vague hints about life in 2015 could alter it drastically might make one wonder if he should claim responsibility for Princess Diana's failure to become queen of England (negating a prediction of the USA Today paper Doc that purchased on October 22, 2015). Then again, he doesn't name-drop her when he describes some of the events becoming undone...
How the Avengers: Endgame Trailer Should Have Ended. Sure, it's awesome seeing several heroes joining in the fray. But when you think about it, some teams are missing their other members. When The Incredibles are seen, it's just Violet, Helen, and Jack-Jack. When the Defenders are seen, it's just Luke Cage and Daredevil. Hell, only Sora and Donald are present among the Sora/Donald/Goofy trio!
Donatello has it the worst. It's just him, implying that the other Teenage Mutant Ninja Turtles, April O'Neil, Master Splinter, and their other allies got snapped.
