If they started using a text classifier instead of their brains to decide who to interview, they would be a) stupid and b) quickly out of money.

a) and b) seem both overpoweringly unlikely, so I think more likely is that they'll just look at the results to see if there's anything interesting about them. (Wouldn't you like to see the results, just to see them? I would, and I have no intention of applying to YC anytime soon.)

Initially I didn't understand why one would think they would be so stupid, and then I remembered what almost every other entity that receives applications is like.