One reason to get the name from the LMS is to prevent (cuz there are always some) the issue of having someone print out a certificate for another person, just by entering the name they want on the certificate. Getting the name from the LMS (aicc_student_name) will prevent that from happening. I know there are more ways after that for someone to get a completion by another person, but this is one less thing to worry about.
There is a thread here somewhere about swithcing the name format from last,first to first last.