I suspect they can't get anybody from production to participate in such work. They're already all down at the corner bar celebrating the fact that they will never, ever, have to see or hear these people ever again. Could you imagine being the sound engineer responsible for maintaining the gains on Christie's microphone? You get to listen to every slurp, smack, and chomp when she eats, and every sob, incomprehensible hypersonic cry-talk, and snot snorkel when she's crying... Yeah. That guy is already three tequilas in when the confetti hits.
But I completely agree with @Callaphera in that the finale could be paced differently. The finale is no place for filler. Just get to final speeches, the juror comments while voting, then the reveal, confetti, AFP, and some conversation and interaction with the free hamsters.
Speaking of confetti...... My fantasy is that by some miracle Jackson goes out a the final three, joins Julie on stage with a stunned look on his face, and as she settles back in her chair, she gently places on piece of confetti on his shoulder as she dabs a fake tear from her eye.