Apple is the tech marketing messiah, why would they announce AirPower at a major product demo and think that it somehow wouldn't be hyped? This is a really strange fumble for them.
It was also listed as a major feature for the new AirPods, that doesn't seem like something Apple would slap on a box knowing they probably weren't going to ship, especially if was a "silly accessory."
I can totally see an engineering team BSing leadership on the product readiness, but there had to be internal pressure on this. Apple knows this looks bad after investors weren't super impressed with the News+ demo.
Your right though, their main problem was announcing it too early. There are probably legal ramifications to this.
Back in the day "intelivision" announced a keyboard component for their console in ads. They didn't ship.. It kept slipping. Then the FTC (government) started fining them for false advertising. So they finally released one (It was junk, we had one).
"Complaints from consumers who had chosen to buy the Intellivision specifically on the promise of a "coming soon" personal-computer upgrade, eventually caught the attention of the Federal Trade Commission (FTC), who started investigating Mattel Electronics for fraud and false advertising. "
If they end up releasing the product, say, a year from now, nobody’s going to say “but you cancelled it before!!! how dare you!!”
I'm imagining some engineering teem at Apple telling their bosses "yeah, it's almost ready" and the bosses believing them without really caring, because it's just a silly accessory and no big deal, right? And then since the AirPods 2 announcemen, the internet has been rabid with anticipation for AirPower. announcing it is cancelled is a better PR move than letting that internet fanboy frenzy turn into frustration with delays.
I wouldn't be surprised if we see AirPower turn up again in a years time.