Harry Potter and the Cursed Child utilizes a very Back-to-the-Future-Part-2-like alternate universe in which Albus and Scorpius realize the dangers of messing with time. This was a lot of fun for the stage, but it has been so overdone in film that it would hardly wow audiences of a Cursed Child movie. Additionally, the play is over three hours long, so aspects of the plot must be cut for this Harry Potter sequel to make it to the screen. Since Albus and Scorpius must be unsuccessful in traveling back in time, cutting the alternate universe plotline makes sense.

Of course, this would be the most significant change for a Harry Potter and the Cursed Child movie since this plotline is a substantial aspect of Albus and Scorpius’ story. Still, since Delphi’s goal is later to go back in time and stop her father—Lord Voldemort—from killing the Potters and thus bringing about his downfall, a Cursed Child movie could jump straight to this objective instead. If Albus and Scorpius discover through their attempts to go back in time and save Cedric Diggory that going back that far with a Time-Turner isn’t possible, it could inspire Delphi to try something else.