Just some general comments:
More research just means he has to search K-Bikes.com
My old car has some clutch 'squawk' when my wife drives it, but not when I do. She uses the clutch like it's stop and go at any engine rpm, whereas I use the clutch at 'sweet spot' rpms in each shift.
What rpm and in what shift are you getting this? Is it low rpm pull away, shifting over 3K rpm or just shifting up/down all the time?
I can't believe at 4K miles your clutch is gone, but you can open the throttle on a hill climb in high gear from say 30mph and see if the tacho runs up fast. Or if you are also hearing squeeling whilst powering with the clutch out - then you have clutch slip and that's a positive for the dealer to do a big fix.
There are two possibilities for a noise when the clutch makes or breaks during shifts. The most common is a very dry clutch and plate which is good and it's a bit like a disc pad squeal. I dont think it's telling of bad news ahead and might go away as the clutch beds in. Perhaps look at your clutch change technique. If you can learn clutchless or near clutchless up shifts then you are on the way to not making big demands on it. Sitting at stop lights with the clutch held in is bad practice to avoid, as is very rapid pull aways. The second less likely possibility is the clutch slave bearing.
The mechanic probably knows that if your clutch has been worked hard from new perhaps unintentionally and the friction material has glazed over, it's a very expensive labor job to change the disc.