Ha ha! I think this is pretty typical response for the Olympic high hunts. 95% unsuccessful and the 5% that are don't talk.
Probably less than 5% success.
I'd say the odds are much higher than that for the guys who actually try. Which not many do, most plan the hunt, go up there see the terrain spend part of a day (maybe) and head home. I know plenty of guys who have planned it for months, then never even got out of the truck once they got up towards the trail head. It's been a long time since I've been up that way in september, not sure I the labar gate is still closed for it or not.
You are definitely right in that the successful hunters aren't gonna talk, and with good reason, the area I've hunted is a very small wilderness area and not much extra room for another set of hunters.