"It must be true because I read it on the internet"
It's a sci-fi story, nothing more, nothing less.
The arguments for or against any aspect of theology, spiritualism or reincarnation are so far off-topic for this forum I'm not going to go through them even briefly.
I'll make do with just this one quote, in direct reference to the poster's claim on Quora...
What possesses a man of Stevenson's intelligence to chase after chimeras and produce thousands of pages of detailed reports that amount to a heap of rationalizations? As Michael Shermer succinctly put it: "Smart people believe weird things because they are skilled at defending beliefs they arrived at for non-smart reasons." Stevenson spent about half his life trying to find support for his beliefs in reincarnation and their relationship to medicine. The beliefs came first. The intelligence was applied to confirming the beliefs. I don't think he is unique in this regard.
 (Quoted from Quora)
"is a true Marvel and I can confirm the plot of the movie is not fictional at all because the topic of Afterlife and Reincarnation is already “scientifically proven” by the books and research of scientists like Dr. Ian Stevenson..."