Jung should beat Kozlov, but so should have Adams and probably his first round opponent. Kozlov was bagelled in the first set, not sure if you noticed that.
I think Thatcher is probably the second strongest player left. Does that mean he will make it to the semis and lose to Ramirez? Maybe, or maybe not since matchups play a role but I wouldn't be surprised to see that. The top part of the draw is really weak and anyone beating anyone is not surprising, since someone has to win.
I dunno about you, but I have been waiting for Nevelo to have some results for a couple of years now, I think he could be a top 500 player done the line, maybe even a bit more. And Podzus is interesting too, actually.
His first round opponent is also very young and with no pro matches, nothing between them in that match