Flip-Flop of God: More or less what All Hail the King was: Marvel and Iron Man 3 co-writer Drew Pearce deciding to backtrack on The Reveal of Iron Man 3 about The Mandarin by revealing that neither Trevor nor Aldrich Killian were the Mandarin, after director Shane Black said in both an interview and on the commentary that Aldrich was the actual MCU incarnation of the Mandarin. To be fair, Drew Pearce has admitted that he had the idea about the real Mandarin in mind while writing the movie, but that Shane Black was not privy to this information since it had little importance to the movie.
Reality Subtext: In All Hail the King, at the Broken Base that is arguing over the Mandarin's reveal. Trevor mentions he's seen the internet boards, which are "vicious" about this discovery.
Among the proposals for shorts were stories featuring Jessica Jones, Damage Control, and the supervillains Sin and Crossbones. Jessica has since gotten a series on Netflix, Crossbones appeared in The Winter Soldier, and Damage Control is being piloted for a series.
The Stinger of Agent Carter with Dum-Dum Dugan had to be changed from him being in the pool to sitting by it, because the muscle suit Neal McDonough wore wasn't waterproof.
You Look Familiar: Matt Gerald appears in All Hail the King as White Power Dave, prior to appearing in Daredevil as Melvin Potter.