Originally Posted by spideymouse
Well the premise of the show is that it exists in the MCU but is wholly separate from the movies. To show cameos of the TV cast might be overstepping that premise.
Well it can't be wholly separate, as it still has Coulson, who has been in the movies. And it's still about the movie universe SHIELD. Cast members of the TV series could just have a line or two in Avengers 2 instead of assigning it to a random extra, just like Agent Sitwell had. Just imagine instead of an unknown playing Galaga, it had been someone like Agent Skye, Fitz or Simmons. Of course, it wouldn't have been since they weren't invented yet, but you get the general idea.