Retcon

[Raeanne Dimick]

a piece of new information given in a film, television series, etc. that changes, or gives a different way of understanding, what has gone before. Retcon is short for Retroactive Continuity.

[Julene]

(in a film, television series, or other fictional work) a piece of new information that imposes a different interpretation on previously described events, typically used to facilitate a dramatic plot shift or account for an inconsistency.