Anecdotally, I don't really know any "high level" wrestlers who are first generation. Wrestling still is a bit of a fringe sport at the youth level and it's still often hard to even find out how to get involved. Unlike I've seen in baseball, soccer, etc. I don't know any families who are traveling a bunch for youth wrestling tournaments who are new to the sport. Also, while there are certainly those guys who are just elite athletes who first try wrestling in high school, the overwhelming majority of collegiate wrestlers have a room full of medals from youth tournaments. YMMV.