The closest thing that I can think of in the NPC world is formal bid. Apparently it was a big tradition at my school a few years ago. From what I've gathered, it's a night that is chosen somewhat into the new member period in which a sorority brings their new member class to a fraternity house to formally announce their new women. Then typically the new member class's bigs watch over them for the night. So... not very much like what I can gather about a probate at all, but again, the NPC and the NPHC operate so differently that that's not really a surprise.
