A very strange question and is mostly theoretical (well I am a writer, but I don't want to spread Lashon Hara about the Jewish people in my short story)*. But if someone was a great sage and lived at the time of the 2nd temple, would they be able to look at a boy of 13 and say "he has a very strong yetzer hara and will become a terrible rasha if he doesn't marry ASAP" then would they say? Or would that be damaging a little boy and spreading lashon hara? I read that the Baal Shem Tov had visions, so I don't think a rabbi being able to make such a prediction is outside the realm of possibility... Thank you for you patience in considering such an odd question.
*Enough of that in the NT & Quran