I agree with Gryphon and at 20k is normal.
However, if you should detect a discernible increase in noise with higher mileage in could be that your beginning to loose rivets in the clutch dampener plate. Excessive noise beyond what you now hear is usually caused by the dampener plate springs beginning to stack & unstack between the plates. When they stack they press or warp the clutch outer plate. The friction plates are rarely involved as they hold up very well.
This wouldn't be a common problem at 20k. Reported occurrences have been at 35k-55k and up. Unless the rider has been very very hard on the clutch.
Other then an increase is noise with the clutch engaged and in neutral the first sign would be the restriction of the clutch lever & then difficulty getting into 1st gear. When that happens it's downhill quickly and the risk of becoming stranded increases.
Most never have this problem at all even at better then 100k miles.
Just something to be aware of.
Consistent hole shots, racing and sloppy lever work are generally the causes over time.
Stacked springs & plate warpage.

Loose spring example.
