Mesenbrink committed to transfer to Penn State in April after a year at Cal Baptist.
Bravo-Young will attempt to earn the 57-kilogram spot on the Mexican team ahead of the 2024 Paris Olympics pending his transfer.
Nickal was originally set for fight Tresean Gore before Gore pulled out due to injury.
Cunningham, a rising junior at State College Area High School, recorded a 28-7 record his sophomore season and placed first in the district and regional levels at 145 pounds.
The World Championships will take place starting Saturday, September 10, in Belgrade, Serbia.
Aaron Brooks, Nick Lee, and Jason Nolf took home U.S. Open Championships.