Mount Everest, a climber known only as ‘Green Boots’, and the mission to solve a 30-year mystery

The very last paragraph in the article seems to attempt to address that question. I don't see why they'd be willing to spend $150,000 to retrieve a body that they aren't confident is still there. But who knows?

In the past 10 years unconfirmed rumours suggest the body of Green Boots has been moved or buried. But Arnette says he has heard from climbers who insist Green Boots remains in the cave, “right where he’s always been”.