How many correct guesses does it take before its something more?No amount of lucky guesses can result in a proof, due to things like confirmation bias. The plural of anecdote is not data, as they say.
People underestimate the intelligence, imagination, and most importantly memory of 3-5 year olds. The presumption that these things must be true because children are too young to have made them up or heard them elsewhere is unsupportable. It's entirely possible that the child overheard others talking about all of the things they are describing, and/or that those who want to believe will mentally fill in the gaps[0].
One would have to rule out all potential contamination from people, media, etc., provide a testable, repeatable experiment, and provide a real mechanism behind the effect, before any scientific credibility could be given to ideas of supernatural revelations to children.
[0] https://en.wikipedia.org/wiki/Cold_reading