If that is the case then TC is truly off his game. First he him self admitted he misjudged demand for the iPhone 7 Plus. Then if he misjudged demand for the cellular iPad Pro, good lord just keeps me asking why he is in charge.
Personally, as someone who did not care for the first gen 12.9, didn't consider it ever, even mocked it a bit, but has an order in for the current model, I disagree that the 2017 version is a spec bump. It's upgrades and added features are more than just a processor update. If it was just that I'd be buying a 10.5. The 12.9 case is quite improved over its predecessor, both thinner and lighter, key factors for traditional 9.7 owners like me.
Not to mention the Apple Watch launch that was sorely undermined with stock and it took almost four months for some to receive their Watch after the initial launch in April 2015.
For you upgrading from the 9.7 to the 12.9, that's fairly obvious it's a change. But for any previous 2015 12.9 owners in comparison to the 2017 12.9 iPad, it's primarily a specification update
internally. Both the previous 12.9 iPad and the new one are no where near that much of a difference physically. Yes, it's thinner and slightly lighter, but looking side by side, they are the same. That's Not what most would consider a hardware revamp, especially looking at the 10.5 iPad with 40 % reduced bezels resulting in more display Area. I did forget to mention Apple upgraded the camera on the both Pro models from the iPhone 7, so there is that also.
Furthermore, the 2017 12.9 iPad has the upgraded internal updates with Tru-Tone, obviously the A10X and it retained the 4 GB of Ram as the previous model. But it's still an upgrade for some, but certainly not physically from previous 12.9 iPad owners. It's about the added power, Tru-Tone and anything else someone finds value in the new 12.9 iPad.