That information is indeed correct and it has been confirmed by Brian Vibberts at the Brad x2 seminar.
This can't be true. Bruce Swedien actually talked about both Childhood and Smile in an interview with the Black & White magazine on November 5th 1994.
The interview was conducted in New York City at the Hit Factory studio.
(This has been translated from French):
Bruce Swedien : Michael wrote 2 songs for HIStory, which I would say are the best he has ever created... Words of those songs are the most personal and the most beautiful he has ever written. He went above and beyond him self. The horrible things he went thru lately inspired him a lot...
ВLACK&WHITE : These 2 songs you mentioned, what do they look like?
Bruce Swedien : The first one is pretty personal. In this song Michael explains he was not allowed to have a childhood, that he lost it, his voice is awesome in it. The second one is different. Michael wrote it in Moscow, when he was on tour. He was alone and tortured by the false accusations against him. He expressed his feelings writing wonderful words (BLACK &WHITE: Bruce sings us the song he thinks is lovely).
The songs starts off with the sound of rain, this is the rain of Moscow, the rhythm is very complexed...there is an infinity of small sounds merged together, Michael makes drums (percussions) with his mouth.
Bruce Swedien : Michael's capabilities are so vast, he did amazing things for HIStory. In another song from the album, for example, he sang with all symphonic orchestra. He entered the studio with 80 musicians, they played their part and Michael sang in front of them. There was no interruption, it was unbelievable.
ВLACK&WHITE : Which song are you talking about?
Bruce Swedien : About the song dedicated to Charlie Chaplin.
ВLACK&WHITE : So, the version we will be listening to, was recorded live and without interruption?