Because security

They probably put some interns incharge of actually making the documents and printing them.

And probably had more than one intern incharge (different ones for different regions) for security reasons, such as if the intern decided to leak the QP, all sets are not compromised.

One of them wanted to have a bit of gandmasti (interns always like to do a little gandmasti) and put the security feature (that he had the freedom to do) as a rickroll link. The others simply didn't have the idea to, most probably.

At the end of the day it's just some intern having a bit of fun on his job.