It is all unscriptural. When Jesus returns, all eyes will see Him and it will be the end of the world.
This boy supposedly saw people in heaven who rejected Jesus as Messiah while they were alive. Enough said.
The boy said they would know him and be surprised because they knew him. That sounds like Jesus to me.
Just because it was not made clear who the messiah is to the boy - doesn’t mean that God isn’t using this to prepare Israel.
As for the second - there are lots of people not in hell who did not receive Jesus as lord - why else did Paul say that those who did not hear about Jesus will be judged by their conscience?