This boy is a phenomenal singer. However, if I had to place a bet I’d say that his days as a boy soprano are going to be over in about six months.
Historically, have boy sopranos gone on to be equally good singers as grown men? Or is puberty likely to be a death blow to this kid’s singing ability?
I’m sure it probably depends on each person, but one example of a successful transition is Aled Jones, a soprano from Wales who’s still performing and recording today. (Here’s a YouTube video of him performing O Holy Night first as a boy and the later as an adult.)
Thanks for that, SkipMagic, that was a cool video. I particularly liked how he did a duet with his younger self - clever. 
My understanding is that a boy singer’s voice change is a total crapshoot. A boy with the most gorgeous voice can become Pavoratti, Gilbert Godfried, or anything in between, and there is (a) no way to tell which it will be, and (2) nothing you can do about it.