Is the movie an original story about the origin of Joker or does it follow some of the status quo of Joker from decades past?
New story I think that has some hints of various possible origins. The Joker really has no real origin story. This Joker is actually too old to be the Batman Joker.
While it may not work for all characters as defining as Joker, some are best left with as little backstory as possible forcing viewers to fill in their own blanks. The Arkham Series, the 1989 film and the Animated Series from the 90's revealed very little.