Depending on your race, different people will appear and Cho will say something different.
Blood elf: Ah, noble is your lineage! Your people possess GREAT power, and all the terrible burdens that come with it. Equally great has been your suffering. Now I see why you call yourself 'Blood' elves.
Goblin: Well... that's interesting. It appears most of your ancestors died in a fire. Oh my. Your people put themselves at great personal risk in the name of progress! I wish more Pandaren had your initiative.
Orc: Astounding! A lineage of great warriors... From a different world, no less! It is rare for a Pandaren to leave his or her homeland. You are rightly proud of who you are.
Tauren: "Look at that. Your people revere their ancersors as well. And you cherish the land. We have much in common! Ah, but I see your ancestors were nomads, whereas we Pandaren prefer the comforts of hearth and home. You'll find few travellers among us.
Troll: Oh my - as I suspected. Your ancestry dates back to the dawn of the world. Great were the ancient empires of the trolls. I see a spark in your eyes, a powerful will - you wish to be great again, yes?
Undead: How fascinating. I thought you looked sickly - but now I see the truth. Your people suffer under the weight of a terrible darkness. What strength you must have, simply to press on forward.