So is the main story like one of the good timelines. This might sound a little weird but certain what ifs if you change the story are either changing a lot for good and the bad.

I know the cursed child was one of those weird stories but certain what ifs like what if Ron was in hufflepuff or if Hermione or Ron never became friends with Harry would change stuff depending on what happened. Something like what if lily and petunia had another sister or brother would change stuff to.