First off, it is BOLA, not bolo. A bolo is what the Argentine cowboys use like our cowboys used a lasso. By the way, the bola is the State Tie of Arizona. The young man was wearing a tie...so far, I have not seen anything that specified a 4-in-hand, nor denied a bow...but, I have not read the school principle's decree.
My husband never got his. They handed out only the holders in case anyone did something deemed "wrong". Then the students had to wait in line after the ceremony for the real diploma. My husband had family visiting and didn't have time to wait. When he needed proof of education at a future job je got a transcript copy instead.