I do not believe in reincarnation so much as regard it as more likely true than not. While I came across the concept in my teens, it was the process of experiencing/witnessing my own mind/psyche -- in particular, the degree to which certain patterns are ingrained and resistant to modification -- that nurtured doubt that such rootedness could come about over the short course of a single life-time.
If reincarnation exist, and the facts goes on this direction, "original sin" is only the original inability to goes to higher existence level because we had freely chose the worst choice and we must freely choose the right direction toward the Source instead of going with our "ego" .
I wonder just how "free" we are once we are here on this plane, in these bodies. Yogananda himself questioned why our memories are wiped clean each time we are reborn (for most -- no doubt, there are exceptions). This would appear to render us more susceptible to the illusory nature of Maya from the start, less able to discern real from illusory and thus, less "free" to make wise choices. If one accepts the concept of the Divine Play, then one might conclude that if the actors are denied awareness they are actors, it will make for more "drama".