^Right. Every ongoing work of fiction is revised over time. Either different creators come in and bring new perspectives and interpretations, or the same creator has new ideas and reconsiders certain things.
I've recently come to the realization that storytellers and audiences perceive fiction in very different ways. To the audience, a work of fiction is something they experience as a pre-existing whole, so they may be inclined to see it as fixed and permanent, and thus react badly to any changes or discontinuities. But to the creator, that work is the end result of a long process of trial and error, revisions, second thoughts, improvements, and the like. It's that process of questioning and reconsidering the content of the work that shaped it in the first place, so it's natural that the author continues to question and reconsider even after the work is published/released. And so creators may change their minds about what they did in an earlier installment of a series, decide it will be better if it's interpreted differently. Ideally you try to find a way to mesh the old information smoothly with the new so that it feels consistent, but that's not always feasible.