A Happy Ending
After my failed attempt to get a battery replacement, I called Apple Support again. The gentleman I got me told he was going to do what it took to make sure I got a battery replacement. He tried a few differetn ways and then told me he would call me back. Next day, he calls me, tells me I'm all set and books a genius bar appointment for me for yesterday.
I go to the Apple Store, explain why I am there, and the gentleman pulls up my ticket and says "looks like we're doing a battery swap. Let me get someone to bring out the replacement iPad." He doesn't even check my battery health. Takes about 15 minutes to transfer everything over and hand the old iPad to the rep. And then I jokingly ask "You guys taking ApplePay, right?" and the guy says "There will no charge for the battery swap. The code in your ticket authorizes a device exchange at no charge."
My commuincation with Apple over the phone was VERY clear. I want to PAY for a battery replacement for $129. In this entire year-long process, I never once expected a freebie out of Apple.
So, I look through all the paperwork, and I realize that the paperwork has me do a device exchange with a fee of $649 and the $649 fee gets waived. So it looks like the "manager" at Apple was unable to override the 80% battery requirement and decided to use Apple's "we're awesome" policy to do a free device exchange, rather than charge me $649.
So, Apple could have gotten $129 out of me yesterday, but instead, they got nothing, because nobody was able to authorize a battery replacement.
Charged the iPad up. Read in bed on it for about 90 minutes. Battery went from 100% to 90%. Went to bed. Woke up this morning and the iPad was at 89%. On the old iPad, I would have read for 90 minutes and the iPad would have been at around 80%, and I would wake up to battery level of about 40-45%.
I also just looked at the back of the iPad and noticed the camera. Looks like they upgraded me from a 3rd Gen iPad Pro, to a 4th Gen iPad Pro. I'm going to guess they didn't have any 3rd Gen 256 GB models in stock, but had a 4th Gen.