That's very cool and certainly good to hear that Cabela's stood behind their product. I had heard mixed experiences with their wader return policy through the years, but always good to get up to date info and share it with the membership. Without having worn them, I have no first hand experience.
Your story is pretty much identical to an experience I had with LL Bean. I spoke to Customer Service and like you, they encouraged me to send them back. I had only 4 years on them but they were fished hard. I didn't have the heart to send them back, I certainly got my money's worth.
Enjoy those new boots, I hope you get similar milage out of them!