Royals and plebeians might be a little strong. YC folks have a slightly different interface. I think the main differences are that YC usernames show up in orange and there is a link along the top that displays the most recent submissions from YC folks/alumni.
"Royals" came to mind from FlameWarriors - though maybe my predispostion to think of PG as the Philosopher King of HN played a role. Anyway, "Plebians" was just pushing the political analogy a little further. I'll take your word about the differences in interface. I really was just conjecturing.